You can go
here, and find more drivers than you can ever dream of, mostly all beta's. Most work pretty good. I've got a BFG 6800 GT OC, and I"ve tried a lot of those drivers. Some of the later ones give better performance and IQ, but the 71 series and up, seem to have a heat related issue. My temps run average of 55/65, idle/load, but with some of the newer drivers, it increased to 65/80. While that is not necessarily
real high, it's higher than I want mine to be. I've quit using the newer drivers that are "leaked", at least for the time being, there are just to many of them.
The right answer would be, go to the link that Howard provided and download the official driver, after all that's what nVidia says will work best for right now, or they would release a newer official driver. But nVidia doesn't release new drivers very often.
If you want to try somthing else, and after trying many of the drivers listed at the link I provided, I've settle on the 67.03 drivers, which provide a good mix of performance and IQ. But it's really up to you. You can just try some of those drivers and see how they work if you like. It's not really all that hard to change drivers, just takes a little time. Rumor is that the 71.84, 71.90 or somthing pretty close to it, will be the next official release.
One more thought, in the link I provided, there are quite a few "modded" driver sets. You might want to look at some of these, but I've tried some of them, and I can't really tell much difference between them and the regular nVidia drivers, despite claims of better performance and IQ.
By the way, what is there that doesn't satisfiy your needs with the original drivers.