Get the Wii. You get some amazing games and can exercise at the same time...
If you like Banjo and Kazooie, get the 360 because it's going to definitely come out on 360...Damn Rareware for abandoning Nintendo... But if you also like Mario, then DON'T get Banjo Kazooie: Nuts and Bolts. They blow up a Mario head in that game. again, Damn them!