I'd really recommend The Biggest Loser Workout. They've got four different workouts in there (low intensity, high intensity, muscle tone and Boot Camp) and in the slightly-over-a-week I've been using it, I've really been feeling the physical difference and results are already showing.
The best part is, they use past contestants in the background, so they're sweating and puffing right along with you, no over-enthusiastic barbie dolls to be seen!