We all have one that we play with our housemates/partner/whatever when you come home after a drunken night out.

For me whenever I go out with my housemates we very often play mariokart 64 and Goldeneye back and forth for probably two hours.

well usually SSBM but we dont get drunk

wiisports

Its gotta be Wii sports, its hillarious... until someone gets whaked, but even then its pretty dam funny.

Wii Sports, Mario Party 8, Link's Crossbow Training, Warioware, etc... You know, the games which I keep seeing people complain about selling. This has led me to assume most of these people are teenagers and can't legally drink, hence not understanding why these games sell so well. :P

I don't tend to play after going out though, it's usually a night in when the console comes out, so I prefer games where I can sit around and drink in between turns, rather than needing to constantly be attending to the game.

Throwing ninja stars to each other..

halo 3----but not online just in a group--thats fun stuff

Super Monkey Ball on GC, this coordination game while drunk take it to the next level of difficulty

Pro evolution soccer 2008, four drunk guys, a soccer rivalry, amazing goals, Nuff said

Guitar Hero