HardOCP checks the performance and image quality of today's most popular graphics cards in Age of Conan:
We are testing Age of Conan with six different current video cards. In the high end, we will be looking at an NVIDIA GeForce 9800 GX2, a GeForce 9800 GTX, and AMD's ATI Radeon HD 3870 X2. In the more mainstream performance market, we'll be examining performance of the NVIDIA GeForce 8800 GT, the GeForce 9600 GT, and the ATI Radeon HD 3870. These six video cards provide us with a good cross-section of the video cards our readers have expressed that they are most interested in. These video cards also allow us to expose Age of Conan to single and multi-GPU products from both GPU manufacturers.
Check it out over here. The site says the GeForce 8800 GT delivers the best bang per buck in this game.