I have a Wii and 360... love em both.
360 has tha smooth, crisp graphics and a fairly nice library of good games. And obviously the best online network.
The Wii ,at this time, is limited to mediocre games with shitty graphics... however the thing with the Wii is that it is so inovative and interactive graphics are not a big factor here IMO... the gameplay alone is amazing. And they retain the title for some of the best exclusives ( Zelda, Metroid, Smash Bros. ).
PS3 aint lookin so good.... except the graphics. Exclusives? pfff, what, Metal Gear Solid? GTA? All of which will indefinetly be released later on 360. Really I see no point in buying a PS3... might as well buy a Wii and a 360 for tha same price.