This is a tough one when comparing the two companies, especially when there are differences in operating systems, like XP verus Vista, versus Linux, versus Windows 7. If you are running XP, your support for the newest effects of DirectX10 or 10.1 will not be available. I would recommend checking out Tom's Hardware on this as there are differences and you will find many, both indepth and lamens descriptions of differences and features. As a norm, I like nVidia, and always have as years ago ATI drivers sucked, especially when it was an OEM card. In other words a while ago, if you had an OEM 7 series card from Dell, the newest driver from ATI would not work by default and a manual install was needed. Considering Dell drivers usually suck and are behind about 10 revisions for video cards, that was a plague for your gaming machine. I have also had driver signing issues many times which sometimes takes a work around when trying to install on OSes like Vista on up. I have run into very, very few driver problems from nVidia, whether it be OEM or retail. I'm sure you will get arguments over both chipset makers, because there is a definite die hard fanbase for each. So just to be fair, do a little reading up at Tom's or on the gaming sites and let us know what you decide.