At least nVidia provide good linux drivers for their cards ...
I had many random and semi-random lock-ups in X. There was one particular tuxracer course that would require the reset button every time I tried to play it. I went back to the opensource driver - no more 3D acceleration, but at least it wouldn't crash.
Only with the most recent driver version a month or so ago has it been stable enough to use.
Cheers, Carl.
