3.
Body Combat
Sounds like you want to try something intense and challenging. Body Combat is a high energy, martial arts workout that will leave you sweating when done right. Truly any high intensity cardio workout will do, but body combat is a fun, group exercise class that challenges you and keeps your heart rate up for almost an entire hour.
You typically burn around 700 in one of these classes. Cardio will get you the results you want quickly because it's so intense. Your personal level of intensity will determine how many calories you actually burn. If you take it easy and do the basic, level 1 moves then you'll burn calories but not as many. However, if you take it to level 3 and add that extra intensity, you'll probably be sore in the morning but you'll see results.
If you want to lose weight fast, do combat 2-3 times per week, give it your all and eat healthy. You'll start to see results fast.
If you don't have Body Combat at your gym, try a kick boxing or Tae Bo class.
Here's a DVD from Beach Body that is MMA inspired that you might like! Or check out Les Mills Body Combat here!