1st Season: Evander Holyfeild and Trista from the Bachelor (I really don't care about her reality TV credentials, just the fact that she's a Miami alum. It's all about The U.)
2nd Season: Master P, Lisa Rinna (My favorite female soap opera actress), Stacy Keibler, and Jerry Rice.
3rd Season: Emmit Smith, Tucker Carlson, and A.C. Slater (or as he's known to non Saved by the Bell fans Mario Lopez).
If you were to tell me a couple of years ago that there would be a show where random B level celebrities took part in a dancing contest I would have put the chances of me watching it at about 2%-3%. That is the genius of good casting.