Originally Posted by bacon12
Is any card gonna make a 3ghz dual core processor bottleneck? I could see maybe sli or tri sli gtx's, but I doubt any single card will.
Depending on the situation and the game, any system can have a CPU bottleneck with a decent card.
Really all you can do is get the best components you can afford. A 6000+ isn't top of the line, nor is it even with a 3Ghz Core 2 duo, but its well above the minimum and recommended requirements for any game I know of.
I'd just get the best card you can afford so that later on if\when you upgrade your CPU you won't have an underpowered graphics card dragging it down.
A 4850 is probably a hell of a card for the price though. I'd say it'd be a good match for your system.
If you can afford a GTX260 or 4870 though, those would be better... I'd personally recommend the 260 because of the extra memory.
... I guess I forgot to ask, what are you using now? If its anything in the 8800GTS\GT\GTX line or higher, I wouldn't really bother at this point.