For PS3, LBP2, Portal 1 or 2, flower is pretty good (not just for girls, that thing is addictive), Definatly get the ICO collection when it comes out (HD remakes of shaddow of the colossus and ICO), For shooters you will probily want to ask what type, as you could go down the Bioshock/deadspace/half life/MGS little ammo and alot of story games, or the COD/Battlefield/Killzone RAAAAH SHOOT BUHLETS games.
But seriously LBP 1 or 2, really fun, challenging, entertaining, and you can generally build an OK friends list as you play online and work together with strangers, I now have gameshared (shared account details) with an american guy, play regularly on cod with a japanese guy and his friends, and even helped a mum who lived in glasgow play through resident evil, just from meeting on LBP, no other game will do that if you dont already have friend gamers