On that Nvidia page my graphic card shows up in the first section as "GeForce 8600 GTS 0x0400"; what do you make of that? I'm pretty sure that my graphics card would support the 180.xx driver since it's less than two years old and was almost the best from Nvidia when it was released.
I will follow Hotweis' advice and stick with the 173.x driver since it seems
to run Sauerbraten, Tremulous, Alien Arena, and Open Arena pretty smoothly (although I have not tinkered very much with the games' video settings).
Still, if I wanted to install the 180.22 driver what would be the best way to do it, since it is not showing up in Adept (I am using Mint KDE)? Thanks very much for your replies.