I'll throw in my ideas:
Ratchet: Mustachio Furioso, Dan Johnson (RIP).
Spike: Monkey Costume.
Jak: Classic Jak, Armor of Mar.
Sackboy: Yellowhead, Clive Handforth.
Sly: Vincetti Goon Disguise, Pilot Disguise.
Kratos: Cod of War, Chef of War.
Cole: Old Cole.
Sweet Tooth: TM1 Sweet Tooth, TM2 Sweet Tooth.
AND I'M OUT
I think Sweet Tooth has a lot of potential for really varied costumes.
Really any of these would be fantastic.
There's Twisted Metal 1 Sweet Tooth:
Twisted Metal 2 Sweet Tooth:
and Twisted Metal Small Brawl Sweet Tooth: