15 Seconds Of Fury
Quite possibly the simplest game on this site, but with the potential to turn into one of the most brutal. All you need is some friends, a lot of beer, and a really high tolerance. The rest is very easy.
Every 15 seconds, take a sip of beer. Sip enough to fill your mouth. If done properly, a 12 oz. beer should be finished in about 3 minutes. Keep rotating step one until there is one man standing, or on the floor conscious for that matter.
Have fun with the game, but don't get stupid. This is truly a game of endurance and high tolerance so if you don't have either then it might not be for you. Otherwise have fun and drink hard.