Nvidia. The high end is represented by the Geforce GTX 280 which is set to launch tomorrow with graphics cards by a number of different companies. Cards with this version of the chip are expected to set you back $649.
So what do you get with that amount of cash? You get a graphics card that, among other things, supports the PhysX game physics software (which Nvidia bought earlier this year). The press release quotes Chris Taylor, the head of Gas Powered Games, as saying they plan to support PhysX with their upcoming action-RPG Space Siege, saying, "And in the near-future, you're going to see real-time, Hollywood cinematic-level environmental effects on GPUs like the GeForce GTX 280. We're talking about some wicked-cool technology here!" Nvidia also claims that gaming performance is 50 percent better than their last major launch, the Geforce 8800 Ultra. Support for three way SLI support is there and there's also support for CUDA technology which the company claims can offload a number of CPU processes over to the GPU.
In addition to the high powered and highly expensive Geforce GTX 280, there's also the less powerful and less pricey Geforce GTX 260 which will be released on June 26 for the suggested price of $399