I used to do ballroom, which was pretty much just hours of exercise at a time. I would love to do it again, but I doubt I ever will. Rumba is probably the closest thing to it, and I hear a lot of good things about it. Maybe in the future.

Mostly when I exercise now, I want to fit in a) watching a movie or TV show or b) listening to an audiobook while I don't, which isn't really doable with something where you have to concentrate on moves or a routine.