$500 Build

This system can play older games on high settings and should support new games on moderate settings.

AMD Athlon 64 X2 5000+ 2.6GHz Black Edition (Brisbane) Socket AM2 CPU - $100
- 2x512KB L2 cache

ASUS M2N-E (nForce 570) Socket AM2 motherboard - $100

G.Skill 2x1GB DDR2 800 (F2-6400CL5D-2GBNQ) memory - $45
- flexible voltage range, 1.8v – 2.0v
- unbelievable price

Seagate Barracuda 7200.10 160GB (ST3160815AS) OEM hard drive - $51
- 7200 RPM, 8MB cache, SATAII

EVGA GeForce 8600GT 256MB PCI-E video card - $80
- 32 stream processors

Silverstone ST400 400W ATX power supply - $47
- 36A on +12V rail

Samsung 20x DVD±R (SH-S203B) OEM optical drive - $27
- black, SATA

Cooler Master Centurion 534 (RC-534-SKN2-GP) ATX mid-tower case - $50
- black/silver, very basic
- 120mm fans, side vents

GRAND TOTAL = $500

Wiggle Room

If you don’t need the case and/or optical drive, you should definitely upgrade to a GeForce 9600 GT card at ~$150. Other options you may want to consider include doubling the hard drive space for $24 more (ST3320620AS), or even double up on the RAM.