My favorite workout vids are Richard Simmons (he's the only instructor I've seen that has some obese folks in the workout, making you think, hey, if they can do it, certainly I can too!), most notably Sweatin to the Oldies 3. It really gets my heart rate up.
that's actually one of the nice things about the biggest loser dvd's... that it is the contestents huffing and puffing along with you