I'm not really an Nvidia fanboi, I've just never used an ATI/AMD card. My first pc had an Nvidia 7 something and when I upgraded to an 8800GTS I was amazed.
Also with every new driver it just got better and better.
So I've stuck with what I know on my latest build.
However, it looks to me that Nvidia are in serious trouble.
With AMD buying ATI the game changed. ATI got it's own chipset manufacturor.
With Sandybridge and AMDs Fusion CPUs you can see the low end card market disappearing.
Great news for Intel and AMD. The death of Nvidia I would have thought.
Nvidia have lost BFG and XFX. They once ruled top, middle and bottom end GPU ranges. Now they are having modest success in the middle with the 460.
AMD are all over the top end (Fermi don't even figure in the main part of Steam's recent survey) are doing ok in the middle and, as I say the bottom end will likely disappear.
Also Nvidia don't have a x86 licence.
Sadly I could see Nvidia going under which would be tragic for the gaming industry.
I have to say that for my next upgrade I might try an AMD card for the first time