wii if you like mario and zelda games but not that good graphics
xbox 360 if you like good racing games // shooters and graphics
you shouldnt buy a ps3 now, maybe in a year of 2 not that many good games yet -> the good games for ps3 are also on xbox 360 for now

I think the wii is better, and will be EVEN better when some more games come out (i.e., Smash Bros.)