Motherboard: Gigabyte S3
Processor: Intel Dual CPU 4.0 Ghz
RAM: 2GB
VRAM: 512MB
HDD: one 232 and one 108 GB

Motherboard: Gigabyte M61P-S3, with an extra fan i mounted on the Northbridge
Processor: AMD X2 4800+
RAM: 2 GB Patriot
Graphics: 8600 GT
Sound: On-board
HDD: 40GB Maxtor IDE, 80GB Western Digital IDE, 320GB Western Digital SATAII
OS: Windows XP SP3
Optical: CD+-RW/ DVD-ROM, not sure of the brand
Case: Old Raidmax case
Monitor: GEM 14"(w00t!)
Keyboard: Logitech Access PS/2 (good keyboard, though the f-key is a little annoying)
Mouse: Logitech USB Optical
Have some problems with the nForce 4 chipset. It likes to corrupt things.

AMD 3200+
2Gb DDR1
ATI Radeon 4850 512GB
Samsung Spinpoin 1T
Gigabyte K8 triton
LG DVD Writer
LG 21 Widescreen Flatron
Logitech Wireless Keyboard and mouse
Canon MP180
Case: Plastic and black with one side transparent
Windows XP 32bit

Mobo: FOXCONN 9657AA
CPU: Intel Celeron E1200 1.60GHz
RAM: 2GB DDR2
GPU: Nvidia GeForce 8400GS
HDD: WDC
eHDD: WD
DVD-RW: Optiarc DVD-RW 7200A
Windows 7 Ultimate 7600.16385

Currently I play with :
Model : AMD Athlon(tm) XP 2700+
Speed : 2.16GHz
Mainboard : octek KT600-823x
Total Memory : 1GB DDR
NVIDIA GeForce FX 5700 (PS2.0, VS2.0 94MHz, 128MB DDR 2x100MHz, AGP 3.00)
Audio Device : Creative Labs Sound Blaster X-Fi
Windows System : Microsoft Windows XP Home 5.01.2600 (Service Pack 3)
In a weeks time I will get Acer Aspire 8530g laptop which will be no 1 machine
Vista
Processor: AMD Turion RM74
RAM: 4096 Mb (2 x 2048Mb)
ATI Mobility Radeon HD 4650, 1024Mb
Screen: 18.4" WUXGA Full HD 1920 x 1080
I also own 2*Xbox 360, PS3, Wii and DS.

Intel Quad 9550, 4GB of Corsair 1033 RAM and an EVGA GTX 275.
It kills pretty much everything... probably last for years, given how slow PC games have been pushing the tech lately.

Nice. I went with a high-end core 2 duo to save costs instead of going quad. The GTX 275 wasn't available when I built my machine, though, so I have the XFX GTX260 Black Edition. 4GB of OCZ DDR2.

Did you get a MOBO that can upgrade to a quad? More processing cores is fast becoming more important than a better GPU.

AthlonXP 3000+
1GB PC3200
GeForce 7800GS 256MB (AGP)
X-Fi Xtreme Music
160GB HD
120GB HD
ViewSonic A90f+ (19" CRT)
Logitech Internet Navigator keyboard
MS Wireless Laser Mouse 6000 (the older all silver model)
Creative T2900 speakers
Sennheiser HD580 headphones (connected to a custom built META42 headphone amp)
Logitech Driving Force wheel
MS Force Feedback 2 joystick
MS Precision Pro joystick
CH Flight Sim Yoke
CH Pro Pedals
MS sidewinder gamepad pro
MS wireless receiver for xbox360 controller

Yes, my motherboard can support the Core 2 Quads. Socket 775. I would need to flash my motherboard's BIOS though.