Well, I'd love to have this:

CPU: QX6800 Quad Core
Mobo: Good 680i or 975X mobo
Graphics: 2x 8800 Ultras in SLI
Monitor: 24" Dell Ultrasharp
Hard Drive: 2x WD 150 gig Raptors for OS, 4x 1 TB drives
Sound: E-MU 1616M 16 channels with a home theater speaker system
Case: Antec 900
Cooling: Phase Change!
PSU: 1 kW PC Power & Cooling *drool*
RAM: 8GB Quad Channel ~ Yes, it's true
Keyboard: Logitech G15
Mouse: G5 7-button, or Razer Copperhead probably...
Headphones: Sennheiser HD555, would prolly need another one for gaming since this lacks a mic..

...and what the hell -- throw in a TV tuner in there too! And of course, get it to look nice and glowy. :)