Any JUST DANCE games are great! Since we didn't have a Wii at school I would use my laptop and from youtube play videos. The kids loved it. The only downfall was the time it took to buffer was ridiculous. The price for a Wii has gone down but after doing Lesson #2 for Technology in P.E. course. I am leaning towards harassing my school for an Xbox 360 with Kinect. The Nike + Training game looks to be like a PX90 workout.
I have been asked about them and I would love to do it. the problem that I see with it is you can only have a max of four students working at a time. you could have students doing it in the background but they do not get the instant satisfaction like the players playing would with a final score. I have thought about doing it as part of a circuit though.