Here’s my version

Cartoon - tempest shadow from MLP movie (stone bombs & tempest shadow armor unlock for demoman)
Web - blitzo from helluva boss (blitzo’s attire for sniper,spy,and medic/blitzo’s flintlock unlock for the spy)
Valve - ellis from L4D2 (M79 unlock for demoman/bullshifters shirt for scout)
Non-valve - chuck greene from DR2 (Chuck Greene’s jacket for heavy,spy,sniper,engie/paddlesaw unlock for pyro & heavy)

the REAL team up for characters  
cartoon: chrysalis  
web: Vsauce micheal  
Valve: nick  
non Valve: master chief

Hasn’t Nick joked about horse meat being delicious before?

@Lordryu  
If we’re going by that logic, here would be my dream team (complete with their TF2 items):
 
Cartoon - Revy from Black Lagoon (Cutlass pistol for Scout/Engie and her tattoo for Scout)  
Web - The Angry Video Game Nerd (Super Scope rocket launcher for Soldier and the Power Glove for Engie)  
Valve - Coach from Left 4 Dead 2 (Tactical Shotgun for multi-class and his shirt for Heavy)  
Non-Valve - Boone from Fallout: New Vegas (His hunting rifle and beret for Sniper)

Trixie and Strong Bad - Cartoon characters  
Nostalgia Critic and Tycho - Web characters  
Nick and the Heavy - Valve characters  
Garrus and Max- Non-Valve gaming characters
 
I can see the comparison.

That would be fucking hilarious

I just want to hear the Nostalgia Critic and Trixie talk.

I’d play it

Okay, this would be amazing.

I actually agree. Somehow, a version of this game with Nostalgia Critic, Strong Bad, Heavy AND Trixie or some kind of pony in the same setting would be a recipe for awesome!