Nerdiest PC would have to be running Linux.

As for gaming. Well this is what I have:

Core 2 Duo 2.13GHZ
nVidia 7800GS
2GB DDR RAM
21" widrescreen
450w PSU

Most people seem to like to waste their money on the best though, such as SLI 2x 8800GTX (I think they have 768MB RAM), 64-bit OS with 4GB+ (I remember seeing someone who had 16GB, just for games which is the biggest waste of money) RAM and quad-core. I mean, that's great I guess, but I can run any new games with my system as long as it stays DX9 (Bioshock, full settings, 1600x1050 runs perfect, for instance). Once everything goes to DX10 or DX10.1 then the cards will be cheap.

Anyways, that's just my guess. I've kind of fallen out of the loop on hardware. I'd rather have a workstation rig set up for 3D and design work.