Obligatory Zumba thread.
I enjoy Zumba because it has me sweating and dying in a a short amount of time, yet is easier than running on a treadmill or something. I've yet to reach the point where I find it "fun" like everyone else seems to, but I do find it much more entertaining than other forms of exercise.
I have the Zumba Fitness game on Wii and the Zumba Exhilarate DVDs that I just got the other day. I haven't been doing it for very long and I'm still at the beginner level, but I'm hoping that during the few remaining weeks that I'm in the US I'll tone a little bit.