Another pretty simple game that requires minimal thought, that is the best kind. Only the barest of supplies are needed: people and beer.
Any player has the power to start the game; all it takes is the calling out of a letter. The next player must then say a word that starts with that letter. Play ends when a word gets repeated or the person is unable to think of a word. That person who screws up takes a drink and play begins again with a new letter.