I got the Wii (and the balance board for the wii fit). That being said, I'm not huge on video games (because I am sure if I really got into them, I'd do little else... I don't go into things half-heartedly...
), however...
http://www.youtube.com/watch?v=Vr40MjFwIU8
http://www.youtube.com/watch?v=ZWF9m8ckI1Y
This game is gonna be the shizz... you use the balance board to control your guy.
I can't remember the last time I was excited about any video game.
Presently all I have for the Wii is Madden 08 (awesome), Tiger 07 (incredible), Mortal Kombat Armageddon (very cool), and the Wii Fit (which I picked up for my wife, thinking she'd be the only one to ever use it... I was wrong... it's great).