Tier definitions first, cause it’s important to get that clarified when you make a tier list.
S-tier is always reliable in every situation. You can, and should, probably run at least one of these people in your squad at any moment. A-tier is a solid pick in their role, but has some exploitable weaknesses or some underperformance. B-tier can fill a very strong niche, and may outperform some A-tiers on the right map, but generally are either outclassed or rely on cheese. C-tiers are just lacking something to make them competitive, whether it be reliability or a strong niche.
Also, listing in order of within the tier. Higher up means higher on the tier list. Differences within tier lists outside of B-tier is pretty small though.
S-Tier
Fragger: the go to assault class. Strong guns, strong abilities, good health pool. What does it matter if you can’t do stuff if you kill everybody? You’ve got teammates to do that tricky stuff.
Sawbonez: the go to heal medic. Decent gun choices, great synergy with Fragger, good health pool.
Sparks: the go to revive medic. Revivr. 'Nuff said.
Skyhammer: the go to fire support. Good gun choices, solid and somewhat versatile fire support, good health pool. He’s somewhere between bottom S-Tier and top A-tier, so I put him in S-Tier because he’s free.
A-Tier
Fletcher: Strong engineer class. Decent gun choices, solid ability, good health pool.
Bushwhacker: Strong engineer class. Good gun choices, situational ability, good health pool.
Kira: Strong fire support. Good gun choices, situational (but very powerful) fire support, good mobility but small health pool.
Nader: Strong assault. Good gun choices, solid ability, good health pool.
B-Tier
Vasilli: the king of niche. If you’re good on Vasilli, you clear house. If you’re bad, you cry everytime.
Redeye: the king of cheese. If you’re good on Redeye, you make people very sad. If you’re bad, you make yourself very sad.
Stoker: Can, and probably should, replace Skyhammer as the go to fire support on Underground. Unfortunately, it’s only Underground, Skyhammer is generally better on most other maps.
Arty: Surprisingly strong despite the stigma. The burst rifle changes have been good to him, and his artillery strike has slowly been buffed to the point of being a pretty solid niche pick as a middle ground between Skyhammer and Kira. That being said, it’s still niche.
Phoenix: A good offensive medic that can theoretically swing the tide of a fight with a well-timed heal pulse. Unfortunately, that’s a very big theoretical that Sawbonez don’t worry about. Similar weapon choices too, so Phoenix is basically super outclassed.
Rhino: You want to be that asshole? Pick Rhino on Bridge or Underground and have a pocket Aura. You are now that asshole. Anywhere else and you’re probably kidding yourself.
Aura: You want to be that asshole? Pick Aura on Bridge or Underground and have a pocket Rhino. You are now that asshole. Anywhere else and you’re probably kidding yourself.
Proxy: You’re fast, you backplant, you’re generally a nuisance. Kinda like a mosquito. Unfortunately, you’re about as liable to be slapped as one.
Thunder: BET YOU DIDN’T THINK I’D LEAVE C-TIER FOR ONE MERC DIDJA? Thunder is alright, a little underwhelming, but he fills a niche. He’s likely to receive buffs soon anyways, but even before then he’s not half as bad as people put him out to be. The problem is just that anything Thunder can do Fragger can do better. Usually.
Cloak-Tier
Phantom: Hi Phantom! I’ll be leaving you down here until you figure out what you’re doing with your life. In the meantime, keep terrorizing pubs. And by terrorize, I mean delude new players into thinking they can run straight at people swinging a knife and get away with it.