PC'S will always out perform games consoles as that is where the technology is developed.
Only problem is if you want a PC that is high spec it will cost 2,500 plus.
For example, I've got an Xbox 360 (I know not as powerful as PS3). I bought ghost recon advanced war fighter, which in full HD looks excellent. My mate has a top spec PC which cost around �2,500 with a HD monitor. I had a quick go on the PC version and it was graphically better & smoother. I didn't think it would be possible (having completed the Xbox version) for the game to look any better.
I prefer playing games with a control pad on my 32 HD TV ,so I prefer games consoles. But some people (with money to burn and single) prefer top end PC's.
Nice if you can afford one.