Coup is a devious little bluffing game for a medium-size group. Each player has two secret cards who could be any of 5 different characters, each of whom allows you to perform one or more special actions. These cards double as lives. There are two caveats: 1) you can pretend to hold any character and perform any action but 2) at any point, anyone can challenge an action. If you are caught bluffing you lose a life; if you falsely accuse someone, you lose a life.
It plays from 2-10, but is a good option when you have a larger group.
Good for: beginning/ending a night; large groups; people who know each other well.
Bad for: people who are bad at lying; people who hate elimination games.