Help -- PS3 Game

I've been bored out of my mind, specially now that I have to "rest". So, I want to buy a good PS3 game. I want it to be multiplayer so I can invite friends over to play. I also would like it to be RPG style.

If you know the game Champions: Return to Arms, then you know what I'm looking for. I would be playing COD4, but my parents won't let me buy it because my little brother plays too much. Oh and yes, if it's a good shooter I would look into it.

Please help me find a good game. I would buy the Champions game, as I don't have it any more, but if there's something better out there, I'd rather get the better game.