Another interesting game for parties...if you're willing to help instruct people is "Ganbare Ginkun". It's all in Japanese, but the challenges are pretty fun to figure out and a total blast to play once you know what to do. One of the "challenges" involves you as a baby cherub trying to aim your "pee" in order to put out a fuse and stop of bomb from detonation. From what I can gather from the animations, it looks like the whole point of the game is to impress girls with your skill or something.
It's an *INSANE* kinda game, but that's the sort of stuff I like. My friends and I have a strange sense of humor.