My rig was pretty awesome back when I got it in 2004, but now its just an average PC.
CPU: Intel Pentium 4 530 3.0 ghz 800 fsb
MOBO: Gigabyte P35-S3 (bought this in 2007 when my old mobo died)
HDD: 1x WD Caviar 120gb sata hdd, 1x WD caviar 250gb sata hdd
GPU: Gigabyte 8600GTS (bought this with the mobo since my X800 pro was an AGP card)
RAM: 1gb DDR2 800mhz ram (i think its just generic haha)
Case: Coolermaster Centurion
Keyboard: Logitech G15
Mouse: Logitech G5
^ Yes, I was. 
Like I said I was mucking around.
I forgot the price but it may be somewhere around $13,000.
They came up with an 'extreme machine' rig on whirlpool which has the following specs:
CPU: Intel Core 2 Quad Extreme QX9770 3.20GHz 12MB 775-Pin $1599
Motherboard: XFX 790i SLI Motherboard $499
RAM: DDR3 Corsair TW3X4G2000C9DF 4GB (2x XMS3 2GB) PC-16000 2000MHz $1079
HDD: 2 x OCZ Core Series 128GB Solid State $998
2 x Hitachi 1TB SATAII 32MB Cache Ultrastar $2224
Case: Lian Li V2010 $375
PSU: 1200W Thermaltake Toughpower Modular $415
GPU: 3 x 1GB Galaxy GTX280 $2244
Optical Drives: 2 x Sony BWU200S Internal Blu-ray Drive $1393
2 x ASUS BLT-1814 Lightscribe x18 SATA $84
FDD: Sony BLACK Bezel 1.44 MB FDD $19
LCD/VFD Display: Thermaltake Media Lab $165
Cooling: Swiftech H20-APEX Ultra Plus Liquid Cooling Kit $495
OCZ Technology XTC Memory Cooler $39
3x 120mm Scythe Kamakaze VR LED Case Fan $90
4x 140mm Aerocool Streamliner 140mm Blue Fan $120
Thermal Compound: Tuniq TX-2 $8
Cables: Flexiglow Blue Illuminated SATA Cable, 50cm w/ EL wire $20
Thermaltake A2117 60cm EL Rounded FDD Cable – White $20
OCZ Enhanced VGA & HDD Power Lead With PowerShield™ EMI Control Technology $20
Monitor: 30" Dell 3008WFP LCD ~$4598 (without specials/discounts) X2
Speakers: Creative Gigaworks S750 THX Certified 7.1 $592
Keyboard: Logitech G15 $89
Mouse: Logitech G9 $99
Total: $17293
