PCPartPicker part list:
http://pcpartpicker.com/p/2mSgj
Price breakdown by merchant: http://pcpartpicker.com/p/2mSgj/by_merchant/
Benchmarks: http://pcpartpicker.com/p/2mSgj/benchmarks/
CPU: AMD FX-6300 3.5GHz 6-Core Processor ($109.99 @ Amazon)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.98 @ OutletPC)
Motherboard: MSI 970A-G43 ATX AM3+ Motherboard ($59.99 @ Microcenter)
Memory: G.Skill Ares Series 8GB (2 x 4GB) DDR3-2400 Memory ($76.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($59.98 @ OutletPC)
Video Card: Gigabyte Radeon HD 7790 2GB Video Card ($125.66 @ Newegg)
Case: Corsair 300R ATX Mid Tower Case ($59.99 @ Microcenter)
Power Supply: EVGA SuperNOVA NEX750B BRONZE 750W 80+ Bronze Certified Semi-Modular ATX Power Supply ($59.99 @ Newegg)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer ($16.98 @ OutletPC)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($88.98 @ OutletPC)
Total: $688.53
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-12-19 15:07 EST-0500)
This build is going to be able to play any game you throw at it at 1080p with medium/high graphics. If you want it to cost a little less, just downgrade the psu to about 520w.