The only games I'd ever extensively played with Kinect were Fable: The Journey and Kinect Adventures. They were both insanely cheap (About €1 each) and decently fun. Convinced a friend to get them too, and the achievement hunting/competition was pretty enjoyable
I also played Skyrim and a Forza game (I think?) over at said friend's place, and it was fun. Not "worth getting a Kinect for"-fun, but "kind of funny with friends"-fun.
Either way, I doubt I'll be getting a Kinect again (Or any type of "gaming camera" because its impreciseness coupled with my weird movement/speech make games more frustrating than fun. Especially considering there's so many games that just use the controller.