I'm personally fond of drinking jenga. Take jenga piece and put numbers 1-3 on the pieces. You pull out the pieces and you have to take that many drinks of your beer. Knock over the tower and you have to chug it all.
Another fun one, is a card/trivia game called "Dirty Minds". You have to buy the card game. It's basically involves you guessing a "normal" word like "shampoo" using clues worded in really perverted ways. You get one clue, and each clue that you require to guess the word, you have to take a shot/drink. Works best in groups.