Nvidia 8800 GTX is still better, despite being older and more expensive. I currently have a ATI card right now, and have always been an ATI fan, but I'm disappointed with these cards. I'm thinking of upgrading to an Nvidia, not ATI.
Unless you can download it somewhere else for free, I'm just buying Halo 2 Vista for the Live Anywhere feature, so I can smoke consoles n00bs in Shadowrun and teach em keyboard is twice as better as a crappy controller.
Gamespot is delibretely trying to make the Xbox images look blurry. Halo 2 looks exactly the same on both, and sometimes better with a 1080 HDTV on Xbox 360.
Like what Pop4 said, you MUST own a DX10 video card (and Vista), to take use of DX10's power. If you just own one or the other, it'll only look slitghtly better than DX9.
Alexmon's comments