Zumba

I absolutely love Zumba. It's the kind of work out that is just FUN, and kind of makes you forget that you're working out. Good teachers give you a low-impact alternative, if your fitness level isn't super high. It is more targeted toward women, but we have a couple of guys attend from time to time. I've missed class for the last couple weeks because I've been busy, and I actually really miss it.

Zumba has it's roots in Latin dance, but I have one teacher who tends to use more hip-hop music, and the other who uses more latin-style music. Either way, you will definitely work up a sweat, but you'll have fun while you're doing it.