The new Rayman game looks funny as hell. That would probably be the only thing to prompt me to get a Wii. Not much of a Zelda fan. Actually, I haven't really seen any other eye openers for the Wii yet.
I would also get an Xbox360, just for Gears of War. However, FPS tend to run thin after beating them.
PS3 hasn't exactly caught my eye with ANYTHING yet. Looking at some of their games, though, they definitely got some eye candy goin' on.
But so far, I would probably only get a Wii, not for the graphics, but for fun. Looks like a great time waster with some friends and beer...and football helmets. That is so nobody breaks a nose from the nun-chuks...