Which nVidia Geforce card are you looking at? Which ATI Radeon? The intel GMA x4500 is no good for gaming so that can be disqualified from the start. Your best option is to get a cheap separate card like an HD 4670.
There must be a specific reason you are asking. The best thing you can do is give us the straight question. Do you have a PC that you need to upgrade or is having video issues with games or other apps. Post your system specs, budget, and what you are trying to accomplish.
If this is a general question, I suggest just doing some reading on the subject.