Intel:
Case - Thermaltake Armor or Antec 900 or Your choice...
Motherboard - Gigabyte P35-DS3R
CPU - Intel Core 2 Duo E6750
RAM - 2 x 1GB Crucial Ballistix DDR2-800 CAS4
Graphics - EVGA 8800GTS 320MB
Power Supply - Corsair 520HX (From buy.com)
Hard Drive - Seagate Barracuda 7200.10 320GB 16MB Cache
Optical Drive - Sony NEC Optiarc DVD Burner
Optional Aftermarket HSF - Arctic Cooling Freezer 7 Pro (From svc.com)
I would go with this build
And you can save money by getting E6550 and Asus motherboard
Newegg.com - Intel Core 2 Duo E6550 Conroe 2.33GHz 4M shared L2 Cache LGA 775 Processor - Retail
Newegg.com - ASUS P5K SE LGA 775 Intel P35 ATX Intel Motherboard - Retail