The best exercise for you is the one you love doing. At some point, you may wish to add light weight training to your routine -- not to build "bulging pectorals" (you have to do some serious weights to look like Ahhhhhhnold!), but to build muscle and help burn fat.

In the beginning, though, find something you love to do, and do it with all your heart. I like to toss some CD's into the stereo, and dance while I'm sorting laundry.