This is a Personal Hero Tier List for your active Hero (not Squad Bonuses), its from my personal experience and you are welcome to challenge/ask questions! Let me know if you would like a support hero tier list.
FAQ:
Tier S Heroes are slightly better than their A/B heroes.
Rarity between Epic/Legendary/Mystic are a small percent, don't worry too much if all you have is an Epic Hero!
Rare Heroes are useful too! You should focus on getting an epic but don't worry about the rarity early on.
You get 90% of the XP invested back when retiring a hero, don't be afraid to experiment
Tier S
Soldier
Special Forces Banshee- Best Warcry, Highest DPS per shot
Urban Assault Headhunter – High DPS potential but Ammo intensive
Constructor
Power BASE Knox – Decoy for the saves, boosted/healing defenses
MegaBase Kyle – Boosted/bonus HP defenses, increased passive damage
Ninja
Dim Mak Mari – Smoke bomb specialist with aoe dps and shield regen
Brawler Luna – Both abilities are useful, good bonuses
Outlander
Ranger Deadeye – Best DPS Outlander with pistol skills
Pathfinder Jess – Quick, Best for farming materials and llama (just beats recon scout with pinata bonus)
Tier A
Soldier
Shock Trooper Renegade – AOE Shockwave and best vulnerability
Centurion Wildcat – Best Support Soldier
Master Grenadier Ramirez – AOE Grenades with residual effect
Constructor
Base Kyle – BASE is very good
Tank Penny – Best Melee constructor, BASE is lacking
Sentinel Hype- Decoy/Plasma combo can be deadly, Base is outclassed
Ninja
Swordmaster Ken – Best Melee DPS and abilities
Shuriken Master Sarah – Best Throwing Stars, good aoe/dot
Dragon Scorch – Best Dragon Slash, DSlash increases resistance so they can survive
Outlander
Recon Scout Eagle Eye – Overall great for Farming chests or materials
Enforcer Grizzly – Most powerful Teddy
Shock Specialist A.C. – Best Shock tower
Tier B
Soldier
Rescue Trooper Ramirez – More well rounded Survivalist
Warlord (Mercenary Jonesy) – Well rounded Support Soldier
Survivalist Jonesy – Self heals and lots of stat boosts
Commando Spitfire – Focuses on "Goin' Commando!!!" skill which is outclassed IMO
Constructor
Controller Harper – Decoy ability is great, BASE and DPS are lacking
Electro-Pulse Penny – Is outclassed by other classes, poor BASE drop
Kinetic Guardian Bull – Abilities and Base don't work well together, BASE out classed
Plasma Shielder Izza – Ability focused, poor BASE drop
Ninja
Poisoner (Smoke Assassin Venom) – Good DPS and DOT, Good ability combo
Assassin Sarah – Needs to constantly attack or loses buffs, lower energy cost for heavy attacks is situational
Stonefoot Crash – Good Stun ability, nothing else special
Skirmisher Edge – No Unique attributes, jack of all trades no specialties
Outlander
Phase Scount – moves around quickly, can gather decently fast
Trailblaster Buzz – Both skill require limted charges, skill bonuses too spread out
Striker A.C. – Punches are stronger but they still don't hurt Husk much
Vanguard Southie – Energy regen is nice, still worse than other choices for resource gathering
Tier C
Soldier
Support Specialist Hawk – Wasted skills on getting ammo back
Constructor
Hotfixer Hazard – BASE out classed, no good abilities
Ninja
Fleetfoot Ken – speed/ fall damage perks are a waste
Outlander
Trailblazer Quinn – Like Trailblaster but loses out due faster movement on player tiles stat
For the most part, everyone has a vague understanding of healing in Tarkov. All the time we see and try to emulate what the top tier players do, but ...