$10 thrift store find that I upgraded from E2140 Pentium dual core, 2GB RAM, and some 256MB ATI RADEON HD2400 XT. Upgraded + cleaned nicely, decent for XP games. It's complete, the only thing I might do is add an SB Live or Audigy at some point.

HP Compaq dx2300 midtower
Intel Core 2 Quad Q6600 2.4GHz quad core processor (was a 1.6GHz Pentium E2140)
4GB DDR2 RAM (max, was 2GB)
160GB 10,000RPM WD hard drive
80GB 7200RPM HD
DVD/RW drive
DVD-ROM drive
300W power supply (upgraded from 250W stock)
AMD RADEON HD6570 1GB PCIe video card (upgraded from ATI RADEON HD2400 XT 256MB)

dat ass

The guts

Product key + HP sticker

BIOS screen

Speccy + temps

Programs and games GALORE! Dolphin doesn't run most games very well but Super Mario Sunshine is playable.