Try this custom built, I chose the parts myself =] (and its a simple one)
CPU: Intel Core 2 Duo E8200 / 2.66ghz / 1333FSB / 6mb Cache
Motherboard: Gigabyte GA-EP31-DS3L (4x DDR2, 4x SATA, 1x IDE, Gigabit Lan)
Hard Drive: Western Digital Green Power 500GB 7200RPM 16mb SATA3gbs
Memory/RAM: Corsair DDR2 2gb PC-6400/800
Monitor: Asus 22" VW223B Widescreen Black LCD
Case: Thermaltake M9 Midi Tower
Graphics Card: Asus 8400GS 512mb DDR2 PCIE2.0 DVI VGA HDTV HDCP
Keyboard and Mouse: Logitech Cordless 1500 Rechargeable Desktop OEM
All together the price should be around $850