PS3 for sure, hdmi, blue-ray, 'not childish' games (no offence), free online(PSN) what else do you want?
Tho WII is not bad either, but you got to like the games, like mario and the other nintendo games if you want a wii :)
I got a wii and ps3.. PS3 is better... But its funny cuz i have all the good games for the wii... Like the only good games for it... Conduit, Metroid prime Trilogy, SSBB, and Zelda. Everything else blows major chunks.. (yes including mario galaxy and the mario kart racing crap).. Anyways PS3 rapes the wii, anyday.. But the wii has some good games tthat i like to play every now and then.