Play flip cup.
Get two equal teams, lots of beer, a table you don't mind getting wet, and plastic cups.
1) Decide how much full to fill the cup with beer.
2) Cheers, and then drink the beer.
3) When the beer is gone, place the cup on the edge of the table, bottom hanging off the side a little.
4) Flip the cup onto the opening side.
5) Once it it on its side, the next person down the line drinks their beer and trys to flip the cup.
It's a race and it has team work. It will get you drunk fast.