Here's a list of 10 different dance fitness Youtube Channels that are worth checking out:
Other than Wii Just Dance (like competitive dance karaoke), Zumba is all I've had direct experience with, but it was a blast. Here's a sample with Joy and Manuel who were my teachers:
(Apparently it's good for not just fun, camaraderie, and coordination, but also for the cognitive challenge of continually learning new routines. I've also anecdotally heard that it has improved people's sex-lives, which I think makes sense with exercise generally, but maybe moreso with something that has room for more self-expression)