PS3 purchase?

Can anyone suggest games that should warrent me buying the system, I kinda want one. I have looked into MGS4 and it looked insanely boring. Killzone 2 looks good and I enjoyed the first one. But, besides those 2 games, what else is there. I already own a 360 and Wii and I just want to know is buying a PS3 is justified in my situation, $600 is a lot. I don't give a crap about graphics, just good games. Please, no blatant fanboyism.