1. Every single player (Mario Party)
The Mario Party games revolve around players competing in a series of fun mini-games while travelling around a game board, trying to collect as many stars as possible. The player with the most stars at the end of the game is the winner. Good, clean, innocent fun. Well, until the first person steals a star, that is. That's when s**t gets serious. After the first blow has been dealt, Mario Party becomes a game all about holding grudges, avenging losses and just straight up being a b**tard. Every single person playing becomes a rage fuelled hate monster that will happily screw over their best friend for a fleeting chance of glory. And you know what? It's absolutely flippin' brilliant. This is one of the very few cases where being a jerk-off actually adds to the fun of the game. If you've never played a Mario Party game before, hunt one down (I recommend Mario Party 4 on the GameCube) and prepare to become an asshole. And prepare to love it...
I've probably missed you're favourite gaming jerk, haven't I? I'm such a douche. Let me know who I've missed (and how much you hate me!) in the comments below.