You can do a better build than that for $600
I don't know if you need Windows or not, but here's what I got for both.
With Windows:
PCPartPicker part list:
http://pcpartpicker.com/p/j4O1
Price breakdown by merchant: http://pcpartpicker.com/p/j4O1/by_merchant/
Benchmarks: http://pcpartpicker.com/p/j4O1/benchmarks/
CPU: Intel Core i3-3220 3.3GHz Dual-Core Processor ($129.99 @ Newegg)
Motherboard: ASRock B75M-DGS Micro ATX LGA1155 Motherboard ($61.97 @ Newegg)
Memory: Corsair 4GB (1 x 4GB) DDR3-1333 Memory ($17.99 @ Newegg)
Storage: Western Digital Caviar Blue 500GB 3.5" 7200RPM Internal Hard Drive ($58.88 @ NCIX US)
Video Card: Sapphire Radeon HD 7850 1GB Video Card ($176.97 @ Newegg)
Power Supply: Corsair Builder 430W 80 PLUS Certified ATX12V Power Supply ($27.99 @ NCIX US)
Optical Drive: Lite-On iHAS124-04 DVD/CD Writer ($14.99 @ Newegg)
Operating System: Microsoft Windows 7 Home Premium SP1 (64-bit) ($90.37 @ Amazon)
Total: $579.15
(Prices include shipping, taxes, and discounts when available.)
Without Windows:
PCPartPicker part list:
http://pcpartpicker.com/p/j4Pk
Price breakdown by merchant: http://pcpartpicker.com/p/j4Pk/by_merchant/
Benchmarks: http://pcpartpicker.com/p/j4Pk/benchmarks/
CPU: Intel Core i5-3450 3.1GHz Quad-Core Processor ($179.99 @ Amazon)
Motherboard: ASRock H77M Micro ATX LGA1155 Motherboard ($69.99 @ Newegg)
Memory: Corsair 4GB (1 x 4GB) DDR3-1333 Memory ($17.99 @ Newegg)
Storage: Western Digital Caviar Blue 500GB 3.5" 7200RPM Internal Hard Drive ($58.88 @ NCIX US)
Video Card: HIS Radeon HD 7870 2GB Video Card ($199.99 @ Newegg)
Power Supply: Corsair Builder 500W 80 PLUS Certified ATX12V Power Supply ($39.99 @ Newegg)
Optical Drive: Lite-On iHAS124-04 DVD/CD Writer ($14.99 @ Newegg)
Total: $581.82
(Prices include shipping, taxes, and discounts when available.)