From the very begining of Openglide, end of 90s, up to now(opengl 3.0) i always choose an Nvidia processor graphic card...and i must say that it never let me on the spot!
Personally i dont consider Ati cards...because i know, deep in my mind, that i'm an Nvidia Fundamentalist.

If you want to play a game or any graph program using OpenGL (i do recommand it!)Nvidia cards are the best.
An OpenGL Fan!!!