Two people face off. One person says something rude, silly, or just crazy sounding to the other in a whisper. The other person must say the exact same thing only a little louder. Then the first person must say it again but even louder still. This goes on until someone chickens out of saying it.
The person who chickens out is out and the next person steps up to the challenge. This game is hilarious, and fun to play tournement style.