1. Metal Gear Solid 4: Guns of the Patriots
So this was one of the games that I switched to PS3 for. God was it worth it. This was hands down one of the best games of this generation and one of the best games ive ever played. I didnt have a clue what the hell was going on by the end of the story but the uniquely cinematic feel of the entire game coupled with countless funny/clever/ingenious gameplay set pieces made for an incredible experience. This game really opened my eyes to the potential of auterism in games and gaming 'celebrities' being the way forward, this was a Hideo Kojima game through and through.
Multiplayers shit though.
I havnt given this anywhere near the time it deserves yet, but what I have seen has been impresive.