1 - nVidia GeForce 7800 GTX With 24 pixel pipelines, 8 vertex units, and an astonishing 302 million transistors, the GeForce 7800 is touted as the most complex graphics processor ever built. By comparison, an Xbox GPU has 60 million transistors. Like GeForce 6 cards, the 7800 supports SLI (Scalable Link Interface), which is nVidia's dual card solution. Great performance with a price tag to match.
2 - Radeon X1800 XT ATI's latest offering for gamers is the X1000 series, which so far includes the X1800, X1600, and X1300. The X1800 XT is currently their premium card with ultra-threaded 3D architecture, improved memory controller efficiency, and Shader Model 3 support. It outperforms the GeForce 7800 GTX on many benchmarks despite having fewer pipelines, and the core hums along at 625 MHz.
3 - ATI Radeon X850 XT The top chipset from ATI targetted at gamers is the X850, which is currently available in Pro, XT, and XT Platinum Edition versions. There is also a Crossfire Edition for those of you interested in running a system with two graphics cards, though this is prohibitively expensive for most purposes. The X850 can be found for AGP and it's a nice choice for an upgrade if you have the disposable income.
4 - ATI Radeon X800 XT A notch down from the X850, the X800 series includes the X800 Pro, the X800 XT, and the X800 XT Platinum Edition, which differ from each other slightly in clock speeds. Although your mileage will vary a little from game to game, the Radeon X800 XT provides performance comparable to the GeForce 6800 Ultra, and is considerably less power hungry.
5 - nVidia GeForce 6800 GT nVidia's GeForce 6800 series represented the largest leap in game card performance to come along in years. They support DirectX 9.0c and Shader Model 3.0 and are available for both AGP and PCI Express. Note that the 6800 Ultra wants two auxiliary power connectors, so you might want to go with the 6800 GT, which only needs one. An excellent card that should get more affordable now that the 7800s are out.
6 - nVidia GeForce 6600 GT Although very similar to the 6800 cards, including DirectX 9.0c and Shader Model 3.0 support, nVidia has made some changes to make the 6600 series more affordable. They have fewer pixel pipelines, fewer pixel shader units, and the memory bus has been reduced to 128-bit from 256-bit, but they still offer exceptional game performance. AGP versions of this card have also become available.
7 - ATI Radeon X700 The X700, X700 Pro, and X700 XT are some of ATI's mid-range cards, meant to compete with nVidia's 6600 line. They fall roughly between the vanilla GeForce 6600 and the 6600 GT on many benchmarks. You can now get PCI Express or AGP models of this card. A terrific value even before the X1000 cards put downward pressure on the price.
8 - ATI Radeon 9800 Pro A quality card that has become very affordable as newer technology enters the market. The 9800 series features a 256-bit memory bus and eight pixel pipelines. There are 256 MB and 128 MB models of this card, and they've all been priced to sell in recent months. You might also find a deal on the 9800 XT, which is slightly faster than the 9800 Pro.
9 - ATI Radeon X600 XT Radeon X600 cards are essentially PCI Express versions of the Radeon 9600 series. The X600 offers performance comparable to the Radeon 9800 at a lower price, making it a good value for gamers on a tight budget. This card has 4 pixel pipelines, two vertex shaders, and a 128-bit memory interface.