BTW, how's my computer, guys?
> Intel Core 2 Quad Processor
> 8GB system memory
> ATI XFX Radeon 5750 graphics
> 750GB Hard drive
Which C2Q is it? And DDR2 or DDR3, at what speed, and is it in dual channel mode? Should be in most cases, but do make sure.

Anything overclocked? Oh,and which OS.

That should be enough to go on with...
edit: No, ATI is not better for gaming. Neither is Nvidia. True enough, Oblivion and Fallout 3 favour ATI for some reason or other, but "wins" and "losses" gets traded back and forth between hundreds of PC games, or thousands... or however many there are since those two companies were first around.