I too would like to thank Nvidia for their great Linux support. Geforce is the only chip in Linux with full XvMC mpeg-2 decoding AND great OpenGL.
Because of great Linux support I buy Nvidia chips only. Since year 2001 when the first Geforce 2 mx appeared and first 1.0-1251 driver hit the nvidia.com webpage in May 2001
I bought once ATI Radeon 9000 but returned it to shop in favour of Geforce FX5200 (more expensive but thanks to Linux driver worth paying). That was very good decision. ATI Linux driver support is awful and quality is poor when compared to Nvidia. ATI recently updates its driver but is still far far away behind Nvidia in terms of quality and feature richness (no XvMC at all however ATI hardware can do such work).