I've put together a nice list for you should you decide to get a PS3.
For single player there's:
Demons Souls - 60+ hours of gameplay, brilliant RPG
Valkyria Chronicles - 30+ hours of gameplay, very fun strategy RPG
Ratchet and Clank: ACIT - Ratchet as usual, amazing
Ratchet and Clank Future: TOD - same as above
inFAMOUS - around 25 hours of gameplay, very fun parkour-ish aspect and fun electricity gameplay
Motorstorm 2 - amazingly diverse and fun offroad racer
Folklore - pretty weird but fun action RPG
Resistance 2 - pretty much a standard shooter but extremely epic, with imaginative and diverse weapons
LittleBigPlanet - great platformer with a limitless level editor
Disgaea 3 - 300+ hours of gameplay, tactical RPG that's not for everyone but very fun
Heavenly Sword - God of War with a woman, awesome
Uncharted 1 - Amazing story, mind-blowing visuals, likeable characters, great climbing and cover based gameplay and good replay value
Uncharted 2 - same as above times two
MGS4 - Brilliantly epic story and camo based gameplay
Katarami Forever - weird game but very addictive and different if you're into that stuff
Wipeout HD - Best racer this gen I'd say
Upcoming:
ModNaton Racers - LittleBigCartRacing, awesome
Heavy Rain - from the makers of Ferenheit and the same type of game so it should be pretty mind-blowing unless the last part of the game makes your character go super-saiyan again
God of War 3 - he rips off a guys head with his hands
The Last Guardian - from Team ICO, and when have their games been anything but amazing?
Twisted Metal
White Knight Chronicles
Gran Turismo 5
The best thing for me is, not very many of them are mindless shooters made for ADD kids that are too common these days, and most of them are in a wide variety of genres. Plus you get all the multiplat single player games like Assassins Creed 2. It's by far the best system to make a nice gaming combo with your PC. Well, it is for me anyway.
For single player there's:
Demons Souls - 60+ hours of gameplay, brilliant RPG
Valkyria Chronicles - 30+ hours of gameplay, very fun strategy RPG
Ratchet and Clank: ACIT - Ratchet as usual, amazing
Ratchet and Clank Future: TOD - same as above
inFAMOUS - around 25 hours of gameplay, very fun parkour-ish aspect and fun electricity gameplay
Motorstorm 2 - amazingly diverse and fun offroad racer
Folklore - pretty weird but fun action RPG
Resistance 2 - pretty much a standard shooter but extremely epic, with imaginative and diverse weapons
LittleBigPlanet - great platformer with a limitless level editor
Disgaea 3 - 300+ hours of gameplay, tactical RPG that's not for everyone but very fun
Heavenly Sword - God of War with a woman, awesome
Uncharted 1 - Amazing story, mind-blowing visuals, likeable characters, great climbing and cover based gameplay and good replay value
Uncharted 2 - same as above times two
MGS4 - Brilliantly epic story and camo based gameplay
Katarami Forever - weird game but very addictive and different if you're into that stuff
Wipeout HD - Best racer this gen I'd say
Upcoming:
ModNaton Racers - LittleBigCartRacing, awesome
Heavy Rain - from the makers of Ferenheit and the same type of game so it should be pretty mind-blowing unless the last part of the game makes your character go super-saiyan again
God of War 3 - he rips off a guys head with his hands
The Last Guardian - from Team ICO, and when have their games been anything but amazing?
Twisted Metal
White Knight Chronicles
Gran Turismo 5
The best thing for me is, not very many of them are mindless shooters made for ADD kids that are too common these days, and most of them are in a wide variety of genres. Plus you get all the multiplat single player games like Assassins Creed 2. It's by far the best system to make a nice gaming combo with your PC. Well, it is for me anyway.