Follows is the configuration for a PC as recommended by TriniTechSquad members at the given budget, periodically scrutinized and updated.
Intel Version
Case: Antec Sonata III w/ EarthWatts 500W $90.00
Processor: Intel Pentium Dual-Core E5200 2.5GHz $83.00
Motherboard: MSI P6NGM-FD NVIDIA 7100 $60.00
Memory: Corsair XMS2 4GB PC2-6400 DDR2 $46.00
Graphics: Sapphire Radeon HD 4850 512MB $154.00
Storage: Western Digital Caviar Blue 320GB $47.00
DVD: LG Electronics GH22NP20 $21.00
Total US$501.00
AMD Version
Case: Cooler Master Elite RC-330 w/ 350W $50.00
Processor: AMD Athlon 64 X2 7750 2.7GHz $75.00
Motherboard: GIGABYTE GA-M78SM-S2H NVIDIA 8200 $70.00
Memory: Kingston ValueRAM 4GB PC2-6400 DDR2 $32.00
Graphics: XFX GeForce 9800 GT 512MB $130.00
Storage: Western Digital Caviar Blue 320GB $47.00
DVD: LG Electronics GH22NP2 $21.00
Total US$425.00