For a while there, I think it was Andy. His expression after he says that when his family comes out the group is fucked, and you reply "They're not coming!" was so goddamn epic. That whole scene was goddamn epic... ah, episode 2. It almost seems like it's been over a year since I played it
But well, if we're talking about characters who are still alive, I think that Kenny takes the cake for reasons people mentioned above.