Soldier 76:  Reinhardt's massive shield is a problem for Soldier 76 as it blocks all of his attacks, including his Pulse Rifle and Helix Rockets.  There isn't a whole lot Soldier 76 can do to Reinhardt, it's tough for Soldier 76 to get close to Reinhardt due to his Charge ability along with his powerful melee hammer and ultimate (Earthshatter).  Soldier 76's lack of vertical mobility makes it harder for him to avoid Reinhardt's Charge and Earthshatter.  Although Soldier 76's Sprint ability can enable him to run away from Reinhardt if he gets to close to him, further avoiding Reinhardt's deadly close range attacks.

Soldier 76's ultimate Tactical Visor is practically useless against Reinhardt due to his shield.  Reinhardt can protect all his allies behind his shield against Tactical Visor's deadly aimbot.  Plus Tactical Visor does not headshot enemies and is overall less useful on tanks as it's easy to hit them normally without Tactical Visor's aimbot due to their large hitboxes.  Tactical Visor is generally best used against low HP heroes anyways.

As Reinhardt, keep pushing closer to Soldier 76 with your shield out while flinging Fire Strikes his direction, the closer you are to him the better.

Hanzo:  Reinhardt's shield protects all his allies behind it from Hanzo's Storm Bow.  The fact that Reinhardt can move closer to Hanzo while having his shield out makes Hanzo an easier target for Reinhardt's Charge ability.  Hanzo's Sonic Arrow (ability for his team to see enemies behind walls in a small radius) is not really effective against Reinhardt due to his obvious position in the front lines of his team with his big shield out, well seen to his enemies anyways.

Although Hanzo's greatest advantage over Reinhardt is his ability to get to higher up ledges with his climb ability, as Reinhardt has no vertical mobility to chase after him.  This protects Hanzo from most of Reinhardt's abilities, including his deadly close range melee attacks, Charge ability, and safe from his ultimate Earthshatter. 

Fire Strike is Reinhardt's main means of dealing damage to Hanzo, especially when he is high up on a ledge.

If Hanzo launches a Dragonstrike, you will need to drop your shield and strafe out of the way to avoid it, as Dragonstrikes can go through shields.

Ana:  Reinhardt counters Ana mostly due to his large shield, as it will block just about everything Ana can do (besides her ultimate Nano Boost).  Reinhardt's shield can block Ana's Biotic Rifle, Sleep Darts and Biotic Grenades from hitting any of Reinhardt's team behind his shield, all of this can really put a damper on Ana's use during a match.

Normally you will be safe from Ana's Sleep Darts, but be careful when dropping it to launch a Fire Strike as that is Ana's ideal time to throw a Sleep Dart at you which can be devastating for your team as you will not be able to use your shield for a short while.  Although for the full duration of Reinhardt's sleep it will regenerate 1/3 of his shield.

Since Ana snipes from a distance she generally will be safe from Reinhardt most of the time as Reinhardt does most of his damage in close range with his Rocket Hammer.  Although unlike Widowmaker and her Grappling Hook, it will be difficult for Ana to reach higher ground where it will be safer from Reinhardt (since Reinhardt has poor vertical mobility) as Ana's mobility is on the weaker side.  With this in mind, it can be easy to Charge at Ana if she is out in the open as she has virtually no way to escape it besides aiming a Sleep Dart at you while charging.

Ana can also potentially save one of her allies from getting pinned from a Charge by giving them a Nano Boost, which could help them survive the pin as it will reduce Charge's damage down to 150 instead of 300, which is enough to save most heroes.  Ana could also Nano Boost one of her allies, which could allow that ally get around Reinhardt to flank you from behind your shield much easier.

Torbjorn:  Reinhardt's massive shield allows his team to attack Torbjorn's turret while taking cover and move towards the turret while his shield absorbs all the damage.  Furthermore, Reinhardt can use his Fire Strike at the turret dealing a lot of damage to it, with the possibility of also hitting Torbjorn behind it thanks to the projectile's ability to hit all objects in its path.

Reinhardt's Charge actually works against Torbjorn's Turret.  A Charge will slam into and stop right where the turret is placed.  It will totally destroy a level one turret and deal 175 damage to a level two turret, he can then easily take out a level two turret with one additional Rocket Hammer swing.

Reinhardt can attempt to Charge at Torbjorn, but it is a very risky maneuver, due to all the damage he would take from Torbjorn's turret, and then possibly dealing with Torbjorn's ultimate Molten Core, which is very deadly to Reinhardt.

Earthshatter will damage Torbjorn's turret while also stunning it for a few seconds.

Widowmaker:  Reinhardt's shield provides excellent cover from Widowmaker's sniper shots and it can give her a much harder time to get clear shots in.  This lets Reinhardt's team push forward quite easily against Widowmaker.

The drawback of dealing with a Widowmaker as Reinhardt is that he has virtually no chance at taking her out.  Widowmaker has very good mobility with her Grappling Hook as she can use it to get to high ground and away from Reinhardt and all his abilities except Fire Strike.  She has no reason to get close to Reinhardt as her role is to keep her distance and snipe her enemies from afar.

Fire Strikes can be used to throw her off track, but it's generally better used on something that you know it is going to hit so it can charge up your ultimate.

Pharah:  Pharah will be a nuisance to deal with as she will be flying in the air most of time while avoiding all of Reinhardt's attacks, except Fire Strike.  Since she has 200 HP, it will take at least two Fire Strikes to take her down from full health.

As long as Reinhardt keeps his shield out, Pharah will be forced to focus on only targets she is visible with and will usually avoid Reinhardt most of the time.  But she can spam her rockets down at your shield, wearing it out quicker.  Reinhardt will depend on his teammates to really deal with taking out Pharah.

Reinhardt is a good overall counter to Pharah's ultimate Barrage, as he can easily aim a Fire Strike at her while she is stationary and can shield her shots to protect his team from the Barrage.

McCree:  McCree performs decently at tanks, and his abilities work well against Reinhardt.  A few fan fire attacks at Reinhardt's massive shield will bring it's hitpoints down tremendously fast.  In fact Reinhardt's shield is one of the few instances where using the fan fire at a longer range makes sense for McCree since it is so big of a hit area.

McCree can counter Reinhardt's Charge with either a Combat Roll to dodge it or a Flashbang to stop Reinhardt in his tracks followed by McCree's fan fire attack.

Be careful of getting too close to McCree as he can use his Flashbang and fan fire to deal a massive amount of damage to you.  Reinhardt's shield will block Flashbangs, but McCree can actually throw his Flashbang above your shield to successfully stun Reinhardt.  You can kind of counter this tactic by angling your shield up so he cannot Flashbang you, but McCree still might be able to Flashbang underneath your shield in this case.  Only get close to him if you can Earthshatter him quick enough followed by melee attacks or a Charge at him.

McCree's Ultimate Deadeye is weak against Reinhardt due to every one of Reinhardt's abilities.  McCree lines up his kill shots for Deadeye at a rate of 100 HP per second and moves very slow while revving up his shots.  Since Reinhardt has a large amount of hitpoints and the fact that his shield can block it, protecting allies behind him, makes Deadeye very weak on Reinhardt.  You can also Charge at McCree when he uses Deadeye as long as you spot him quick enough and he isn't too far away from you along with having enough health for it.  A quick Fire Strike can also be used from a distance to deal some damage to McCree as he is revving up his Deadeye.  Oh yeah, and Earthshatter will put an end to it as well.

Junkrat:  Not many heroes have ways to deal with Reinhardt's massive shield, but Junkrat can shoot his grenades over his shield, potentially ricocheting off of a wall behind Reinhardt to deal a good amount of damage to him and his team.  Keep in mind that Reinhardt's shield will block everything Junkrat has, including:  mines, traps and frag grenades.

Thanks to Junkrat's mine jumps, he can get to higher ground and avoid most of Reinhardt's abilities, including:  melee attacks, Charge, and his ultimate Earthshatter.  Junkrat can also put a trap/mine down to stop a Charging Reinhardt coming after him.

Since Junkrat is usually able to take cover while lobbing grenades, he is virtually safe from Reinhardt's Fire Strikes.  Although Fire Strikes can be useful for taking out Junkrat's traps and mines laying on the ground if you see them in the distance.

Junkrat's Rip-Tire is very deadly to Reinhardt as it can take him out at full health as it can do up to 600 damage.  Reinhardt will need to rely on his teammates to shoot it down or fling a Fire Strike at it to take it out before it gets to him.  Remember shields can block Rip-Tire damage, but unfortunately tires can also be steered right through shields and then be triggered.

Reaper:  Both Reaper and Reinhardt excel at close range combat and it will be tough for both heroes to face each other.  Reaper's shotguns are very deadly in close range so Reinhardt will need to react quickly with an Earthshatter or Charge.  If Earthshatter is not available just use your shield if you can while your team dishes out damage to him.  If you can't use your shield, just try to get some melee strikes in with your hammer or a Charge at him.  Reaper can easily escape with Wraith Form but if you can land an Earthshatter or Charge at him it can be an easy victory for Reinhardt.

Be careful because Reaper can Shadow Step to a higher ground right around you to shoot down from high above, the only thing Reinhardt can do about that is launch Fire Strikes at him and hopefully rely on his teammates to take care of Reaper.

Zenyatta:  Reinhardt can be a prime target for Zenyatta's Discord Orb (which will amplify all damage taken by +30%).  This spells bad news for Reinhardt.  Just keep your shield out and avoid taking damage directly as much as possible.  This means refrain from using Charge as it will expose you to the enemy much more.  Hopefully you will have a Mercy nearby to heal up any damage done to you and you should be okay.  Zenyatta CANNOT launch his Discord Orb through shields, so keep your shield out to block incoming Orbs of Discord from targeting you or an ally behind your shield.  Keeping your shield out to block shots will waste Orb of Discord's potential.

Reinhardt's ultimate Earthshatter will stun enemies for a period of time giving Reinhardt more time to prevent Discord Orb damage done to him or whoever has the orb around him.

Getting close to Zenyatta can be deadly to him as Reinhardt's melee attacks and Earthshatter will quickly decimate him as long as Zenyatta doesn't focus fire you down with Discord Orb and energy orbs, or Zenyatta can use his ultimate Transcendence to save him.

Be cautious using Earthshatter around a Zenyatta using his ultimate Transcendence as it will block the Earthshatter from hitting enemies behind Transcendence's hitbox.

Reinhardt can actually use a Charge against Zenyatta using Transcendence to push him and his healing effects away from his team.  It is usually a good idea to use Charge for this particular reason often.

Symmetra:  Symmetra's Photon Orbs will go right through Reinhardt's shield damaging it and then hitting anything behind the shield as well, including Reinhardt himself.  This can charge Symmetra's ultimate up faster, quite easily.  Even though Photon Orbs fly slowly in the air, it's still hard to dodge them as Reinhardt due to his slow mobility while his shield is out.  However, Reinhardt's shield does block Symmetra's Projector beam.

Since Symmetra is usually back with her team taking cover while lobbing Photon Orbs or putting up Sentry Turrets, she is usually in the clear of Reinhardt's deadly melee attacks and Earthshatter.  However if she does happen to get close to Reinhardt she will most likely take a good punishment from him as there is not much she can do about it.

It is possible to run into Symmetra's Sentry Turrets as Reinhardt, but it's rare.  Reinhardt's shield does block Sentry Turret beams from hitting him and his wide melee arc swings can easily take them out.

Symmetra's Teleporter (ultimate) is not a job for Reinhardt to go hunt down, as that is a job for other heroes that have greater mobility such as Tracer, Genji, Reaper, or D.va.

Tracer:  Tracer can be very deadly to Reinhardt, because he is a prime target for her Pulse Bomb.  She can blink around your team unnoticed and then throw a Pulse Bomb on Reinhardt's back and potentially take him out, she can then Recall back to safety.  However, Pulse Bombs do 400 damage so it may not be enough to take out a Reinhardt at full HP (of 500).

Fire Strikes and Charge is not very effective on Tracer due to her fast mobility.  If you see a Tracer up close, use Earthshatter quickly to take her out if you can.  Rocket Hammer swings can also easily knock her down and make her easy to deal with up close.

Tracer can actually Blink past a Charging Reinhardt, to prevent getting pinned by a Charge.

Winston:  Winston can quickly leap up towards Reinhardt and has the ability to be very deadly up close.  His short range Tesla Cannon can fire through Reinhardt's shield, potentially forcing Reinhardt to drop his shield to do melee attacks or an Earthshatter to save himself unless his team can provide enough fire power behind Reinhardt.  Even worse is Winston can turn on his ultimate Primal Rage, which can knock Reinhardt and his shield away from your allies.  If you can, Charge a Primal Rage Winston to disable him from attacking your team for a short period of time, then use Earthshatter if it's available followed by melee strikes, and then prey that you will still live through all that.

Winston can provide his team with Barrier Shields too, but it has no effect on Reinhardt as all his abilities can go through Winston's shield, including Fire Strikes and Charge.  It's usually not wise to Charge at Winston from a distance because he can simply leap to avoid it (if he is quick enough), which can put you in a dangerous situation away from the rest of your team.  It's usually only wise to Charge at Winston when he is close to you.

Roadhog:  Even though Reinhardt can use his shield to block Roadhog's Chain Hook, Roadhog can still manage to Chain Hook you from any slight moment when you do lower your shield.  If you can, use an Earthshatter after getting chained in followed by melee strikes at Roadhog.  If Earthshatter is not available, then use a Charge at him or put your shield out to block incoming shots.  Either way, Roadhog can be hard to take down after getting chained in, due to the close support of his allies, his powerful Scrap Gun, and his high HP.  Also Roadhog can still Chain Hook you in while doing a Charge.

Roadhog's Scrap gun happens to be very deadly against Reinhardt's Shield, as it's the most powerful basic attack weapon (besides a Bastion Sentry) that can take Reinhardt's shield down the fastest.  And this is especially the case when Roadhog uses his ultimate Whole Hog against Reinhardt's shield.  Whole Hog will also knock back enemies he is firing at, this can make Charge difficult to do during this time or get close to him to execute melee strikes.  Earthshatter can be used to put an end to Roadhog's Whole Hog though.

Roadhog's Take a Breather (self heal) can be canceled by Charging at him, or by using an Earthshatter.

Fire Strikes happen to be useful against Roadhog since he is a big target that also moves slow, thus making it easier to land Fire Strikes on him, which in turn can rev up your ultimate faster.  You just need to watch out for Roadhog's Chain Hook when launching Fire Strikes as you will have to lower your shield temporarily.  Consider only doing this from longer ranges.

Reinhardt:  Vs another Reinhardt usually results in a big shield dueling Fire Strike battle between the two.  Remember, Fire Strikes can go through another Reinhardt's shield and hit everything in its path behind it.  Oftentimes the winner is the one who has a better supporting team and healer.

With 1 on 1 battles, the one who charges and pins the other one first usually comes out on top.  When two Reinhardts Charge each other, they will both clash at each other and then drop, get stunned, and take damage.

An Earthshatter can also end the battle quickly as it can then lead to an easy Charge or Fire Strike to finish the opposing Reinhardt off.

Shields do not block melee attacks, and when attacking another Reinhardt's shield with a Rocket Hammer melee attack, it can hit both Reinhardt and his shield with one swing.

Genji:  Genji has great mobility and is able to get high up and away from Reinhardt and most of his abilities, from there he can pick at Reinhardt with his shurikens.  Reinhardt can block shurikens with with his shield most of the time, however Genji may be able to get all the way behind Reinhardt's team and harass him from behind, which can be annoying and Reinhardt will depend on his team to take out the wondering Genji as there is not much he can do about it except fling a Fire Strike at him, which can also be repelled by Genji's Deflect.

Up close battles are dangerous between both of the heroes, Genji's Swift Strikes can do an ample amount of damage (even through shields) and he can then use his ultimate Dragonblade up close which gives him very powerful melee strikes (that also works with attacking targets through shields).  Reinhardt can counter that with an Earthshatter followed by a Charge or Fire Strike.  If Earthshatter is not available, I recommend attempting to Charge him to either pin him or to escape from him if it misses.

Also keep in mind that Genji can use Deflect to block Reinhardt's deadly melee attacks.

Bastion:  Reinhardt's Fire Strike is one of your strongest abilities against a Bastion Sentry.  Even though Fire Strikes are slower moving projectiles, that's no problem against a stationary Bastion Sentry.  Since Reinhardt can use a Fire Strike every 6 seconds, this will force Bastion to keep repairing or reposition elsewhere.

Besides Fire Strike, Reinhardt can attempt to Charge and pin a Bastion Sentry, but Bastion can still kill you while Reinhardt is charging.  Charge really only works if it's a relatively short distance.  Mei can also lift up Bastion in places where Reinhardt cannot reach thus making Charge useless in those situations.  Reinhardt's Barrier Shield can help him and his allies get closer to Bastion, but Bastion can tear through Reinhardt's shield very fast in about 5 seconds regardless of range.

Bastion's ultimate Tank Form is a deadly ability, but Reinhardt can actually Charge and pin a Bastion using Tank Form and it will cancel out the ultimate.

D.va:  Reinhardt has some strong counters against D.va, he can use his shield to block D.va's Self-Destruct, potentially protecting his whole team from it while they can still fight and not worry about taking cover.  But it will put a dent into his shield as Self-Destruct does up to a 1000 damage and his shield has 2000 HP.

If D.va gets up close and starts firing her cannons, she can be an easy target to Charge/pin as long as her Boosters are still on a cooldown.  If you can, just use Earthshatter to knock her down first then Charge at her, especially if you know her Boosters are available to her.  Also Earthshatter works through D.va's Defense Matrix.

With D.va's Boosters so readily available, she can easily boost to high up ledges where Reinhardt cannot get up to and she can be safe from all of Reinhardt's abilities except Fire Strike.  D.va's only use of Defense Matrix against Reinhardt is for Fire Strikes, but it would be kind of a waste as she can also just easily strafe to avoid them.

Mei:  Both Reinhardt and Mei are both deadly in close range combat, but who wins?  Reinhardt has the upper hand here thanks to his powerful Rocket Hammer, which can knock down Mei resetting her freeze gun.  Reinhardt's ultimate Earthshatter is also a powerful counter to Mei's Freeze gun, which will knock her down and reset the freeze effect.  Mei's Freeze gun also cannot go through Reinhardt's shield.  Not to mention Reinhardt can Charge Mei unless she can respond fast enough with an Ice Wall or Cryo-Freeze to block it.

Mei's Ice Wall allows her to boost upwards to higher areas where Reinhardt cannot get up to and shoot Icicles down at you, this is devastating to Reinhardt as he cannot do anything (besides Fire Strikes) against enemies that are high up where he cannot get to.

Keep in mind that Reinhardt's Fire Strikes can strike through just about anything, but it cannot go through Mei's Ice Wall or a Cryo-Freeze, as they will both block it.

Reinhardt can use his shield to block Mei's ultimate Blizzard drone (but not actual Blizzard) by simply facing his shield toward the hovering drone to prevent it from flying to far.  Reinhardt's shield will NOT block the actual Blizzard in any way, however Reinhardt can Charge out of the area of effect before he gets frozen.

Zarya:  Zarya is not much of a threat to Reinhardt.  Both heroes generally keep their distance from each other, but Reinhardt can do serious damage to her up close as long as she is unable to use her Particle Barrier to protect her.  Her poor mobility only makes it harder for her to escape Reinhardt's deadly melee attack and Charge ability.  Reinhardt can still Charge Zarya while her Particle Barrier is up and Reinhardt's shield can block both of her attacks from her Particle Cannon (short range beam and explosive charges).

Be careful using Fire Strikes around Zarya, because if she has her Particle Barrier up (or on an ally), she will block the Fire Strike damage and absorb the damage to increase the power of her Particle Cannon.  A Fire Strike will still pass through Zarya's barrier, doing no damage to her and giving her +40 power for her Particle Cannon.

Unfortunately Reinhardt's shield will not have any effect on Zarya's ultimate Graviton Surge, but Reinhardt can actually escape out of it with a Charge.

Reinahardt's Earthshatter will NOT knock Zarya down when she has her Particle Barrier up, and she will absorb the damage as well (+13 to her Particle Cannon strength).  The same thing will apply when her Projected Barrier is on an ally.

Mercy:  It's generally not Reinhardt's job to kill another Mercy and vice versa.  Mercy will make dealing with an enemy tank a lot more difficult with her incredible healing and damage buffing capabilities.

Fire Strikes can be used in her general direction to potentially hit her or her allies.  If she uses a Resurrect, you then have an opportunity to time a Charge at one of the resurrecting heroes, or a Fire Strike.  If there is a lot of enemies being resurrected, then an Earthshatter would be very useful once they get revived, followed by melee strikes.

Lucio:  Lucio is not much of a direct threat to Reinhardt, but his healing and speed auras will give Reinhardt a tough time for sure.  Reinhardt's shield does a good job of blocking Lucio's sonic projectiles and also his knockback (Soundwave).  Lucio can still execute a Soundwave on Reinhardt if he moves into and past your shield first.  Aiming Fire Strikes or Charges on Lucio or his allies will be a lot harder to do if Lucio has his speed aura on and even when it's not on, Lucio still has the fastest basic ground movement speed compared to any of the other heroes in Overwatch, thus aiming attacks at him can be quite difficult.

If you do manage to get close to Lucio, an Earthshatter can be quite useful on him, as long as you quickly take him out before he uses his ultimate Sound Barrier to protect him and his allies from dying.

When Lucio uses Sound Barrier, it's usually best to just keep your shield out to absorb damage until it's over, as it's pointless attacking them when they are nearly invulnerable for a short period of time, so it is best to focus on protecting your allies in the meantime with your shield.