Go Fish Drinking Game
A very simple adaptation to the card game of the same name. Supplies: people, beer, and cards.
Deal the game as you normally would. Anytime you ask for a card and are told to "go fish," you drink once. Everytime you have to give a card to another player, you drink twice, three times for face cards and aces. Everytime time you lay down a pair, your opponent(s) drink twice. It's that simple.