I got the kinect and have been using it for weight loss purposes as well. Right now I've been playing Your Shape: Fitness Evolved and it's really been kicking my butt! It also has a lot of fun classes on the side, like Yoga and boxing that, for me, makes you forget you're even working out for the sake of working out.
I tried Dance Central, but I couldn't really get into it because of the type of music and dancing they used. But, hey! I'm glad it's working out for you.