with so little info there's no helping you really. what types of genres do you like? what do you actually like about the genres? are graphics more important than storyline/gameplay? does new game plus replay value make a game more desirable? should there be an online mode? little or a lot of DLC? need facts man! (or woman :P )
If you want a strong FPS: Battlefield 3. I would recommend Call of Duty Black Ops 2 but I just can't without having played it. It is expected to perform well on the ps3 but I'm not sure. I'll have it tomorrow and can give a better opinion then.
Some unique RPG games:
Demon's Souls *****MUST HAVE FITS THIS PERFECTLY***** Don't let the difficulty stop you, it's a tough but fair game.
Dark Souls (a pseudo-successor to Demon's Souls)
If you already have a 360 then you've probably played these but if this is your only console then I'd recommend checking out some of the Assassin's Creed games.
If you do get assassin's creed games, DO NOT BUY THE FIRST ONE. IT IS INCLUDED WITH Assassin's Creed Revelations I believe.
Another unique ps3 exclusive is Heavy Rain. It's a cinematic game that plays like a movie but gives you choices to make and lets your character move around, check it out on youtube.
That should be enough for you at the moment. You can get most of these and still not spend too much money at the same time as most of these games are somewhat old to moderately new.