Dance Central is.... actually kinda boring. The music generally sucks. It helps to have tunes that people are familiar with. Yeah, I'm not much into discos or raves, but please, there are more song genres to dance to than the pop trash thats on the disc. Yes, its cool to learn the moves and learn to move in a rhythm, but its not cool to be forced to listen to Lady Gaga not once but twice.
Kinect Adventures is a good time, especially as a party game. It gets you up and moving all over the place. And it takes embarrasing photos of unsuspecting players.
I haven't tried any of the other games.