I'd go Wii. PS3 has nothing you can't already play on your 360.
With Wii you can play Mario Galaxy, Metroid 3, Zelda TP, Zack & Wiki, RE4:Wii, Paper Mario, RE:UC
and will play in the near future:
Smash Bros Brawl, Mario Kart, Fragile, FFCC, Tales of Symphonia2, Fatal Frame 4, Spore,
(all the above are (console) exclusive for Wii)
With Wii60 you'll (probably) miss out on:
Metal Gear Solid 4, Gran Turismo 5, FF main series, Uncharted, Ratchet & Clank
But very good substitutes:
Splinter Cell 5 (360), Forza 2(360), Lost Odyssee (360), Metroid (Wii), Super Mario Galaxy (Wii)
Good luck with your choice.











