I have done yoga in the past in a class room and it was very good for flexibility. But now that I work out mainly at home I have not kept it up using yoga DVDs: I did buy one by Rodney Yee, but I didn't like it too much.
I am thinking of trying pilates, like More Than Mat series which has 3 DVDs and you can find this on collagevideo.com. I have previewed them on collagevideo.com and they look great. I can't wait to try them. Janis Saffell, Winsor Pilates and Jenifer Kries and There is Tracey Mallet Renew.
Check out the Pilates section on collage and see what you fancy.
Yen