Yoga is a great exercise for weight loss
There are several different styles, so you might want to look into them on the web before investing in DVDs or classes.
Most styles will give you a full body workout and improve balance and flexibility. I strongly recommend taking a couple of classes to get started if you can afford it and/or can get to one. A good teacher can really help you get into the poses properly without hurting yourself and modify poses that are just a little beyond your skill so that you can do a modified version working up to the full-on pose.
The other benefit of yoga is the mind/body connection. Yoga teaches us how to use the mind to appreciate and train the body and to use the body to calm the mind.
As you might have guessed - I highly recommend it to anyone. Any age or any fitness level.