Why restrict yourself to a single platform?
I play alot of games on my PC due to controlls. I prefer mouse and keyboard for FPS and RTS games, this includes RPGs as well. The consoles lets me play stuff like Guitar Hero, Ninja Gaiden, Dead or Alive, Teken, Assassins Creed (yea I know it is available for the PC, but I was sick of waiting for the title when it came for Xbox I went out and bought the system only so I could play AC), Mass Effect (was originally an Xbox only title, I was furious when I learned it came for PC as well). I don't own a PS3 my self, but friends have me, and I play alot on theirs. BF Bad Company ftw!
Every platform has its own perks and every platform appeals to me. On a note though, as I said I do not own a PS3 nor will i ever. The titles that are PS3 exclusive mean NOTHING to me. Metal Gear is/has/will always be, crap! I love my PC, I love my Xbox and I find it enjoyable to invade the PS3 of mah friends..
