Coinage

For this game you need a small coin, a table you don't mind getting a few small dents in (perhaps use a bread board instead) and a shot glass.

Pour two fingers of the penalty drink in the glass. Place the glass on the table, or several centimetres away from the bread board.

Each player takes it in turns to try to bounce the coin off the table into the shot glass. Depending on what happens you do the following:

If you miss completely, it's the next persons turn
If you get it in, you can nominate someone to drink the contents of the glass. You then get another turn.
If the coin bounces off the glass without going in, one of the other players may 'challenge' you. During a 'challenge' the contents of the glass are doubled and you try to bounce the coin again. If you miss you drink the penalty; if you get it in the challenger drinks.
If you get the coin in the glass three times in a row you can make a new rule that all players must obey (e.g. no swearing, you are only allowed to call people by their surname, etc.)