Come to think about it, the only game where people actually cared for your avatar's appearance that I remember is Fable. But nothing stopped the player from wearing a chicken costume while fighting undead at the graveyard of course.
I do hope appearance (clothing) will influence Rivellon's inhabitants in Original Sin. That could be a new quest: "The town's painter has asked me to equip the bikini armour around the graveyard. I must find a secret way in, for the guards won't let me enter with it. (they're the fellows at the freaking fcc)"
