I used to use 1290X960 on my TNT2 but when I got a Radeon, that resolution was no longer supported so I started using 1290X1024. Amazingly, I can hardly tell the difference and when I use Powerstrip to create 1290X960, it actually looks strange to me!
Funny thing...
I think the best resolution would be whatever YOU think is the best. I think someone said that but yea...