I have a 360 with a Kinect. Currently own Kinect Adventures, Kinect Sports, EA Sports Active 2, Fitness Evolved, and Child of Eden. Also have the demos of Dance Central and Dance Paradise.
Child of Eden is ok. Took a while to get in to it but it's basically a lot of flapping your arms around to computer art. More specifically it's flapping your right hand most of the time and waving your left hand when you see purple stuff. It definitely doesn't have the instant 'wow' that kinect adventures/kinect sports have. There's also only two hours of gameplay so I wouldn't buy Kinect just for CoE. Fitness Evolved however is very very good and so is Kinect Sports. The game I'm really looking forward to is Star Wars... can't wait!
PS - Best Buy currently has a buy one get one free offer for kinect games.