I originally started with classes at my college gym, but after college, I couldn't afford classes, so I got online and got a used copy of Zumba Fitness: PARTY for Nintendo Wii. It's a good workout, fun, and it calculates your calories based on your energy (you wear a belt on your hips that holds the Wii remote so it knows how your moving, how much, and how fast.) The only thing I do not like is that you have to unlock levels to do the longer workouts, and they are all pretty much the same dances, they just sometimes go in a different order based on the length and intensity of the "class." They have, however, come out with the Core workout for the Wii that I haven't tried, yet. Also, the avatars are weird and it's still fun to do, but boring to watch.
Now, the Zumba Fitness: RUSH for Xbox Kinect is AWESOME! (I'm saving up for the Zumba Fitness: CORE workout next.) This game has several different dances, several different mixes, 10+ "classes" to choose from and "real" avatars in various settings that is fun to watch. Also, with the Kinect, it shows in the bottom left corner how you're moving, so it's kind of like a mirror (and we all know that when working out in front of a mirror makes everyone work a little harder!). This game, too, calculates your calories burned based on how much you move and the energy you exert. In a mid-length, medium intensity class, I burned 376 calories; in a full-length, medium intensity class I burned 1,372 calories; in a mid-length high intensity class I burned 1,734 calories. HOW AWESOME IS THAT!? I'll let you know how much I've burned off whenever I get to the other class combinations!
If you don't have a Wii or Kinect, I can guarantee that you can find a class in your area to try out. If it's something you really enjoy doing, then I suggest going to Game Stop and getting a used console and a used game. (It'll save you time and money in the end when you can work out at home!)