[Build Help] Which CPU is best for this $500 budget PC?

PCPartPicker part list / Price breakdown by merchant

Type Item Price
CPU AMD Athlon X4 860K 3.7GHz Quad-Core Processor $71.89 @ OutletPC
Motherboard Asus A88XM-A Micro ATX FM2+ Motherboard $52.99 @ SuperBiiz
Memory G.Skill Sniper Series 8GB (1 x 8GB) DDR3-1600 Memory $48.99 @ Newegg
Storage Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive $48.47 @ OutletPC
Video Card PowerColor Radeon R9 280 3GB TurboDuo Video Card $152.98 @ Newegg
Case Fractal Design Core 1100 MicroATX Mini Tower Case $37.99 @ SuperBiiz
Power Supply SeaSonic S12II 520W 80+ Bronze Certified ATX Power Supply $53.99 @ SuperBiiz
Optical Drive LG GH24NSC0B DVD/CD Writer $13.98 @ Newegg
Operating System Microsoft Windows 8.1 - 64-bit (OEM) (64-bit) $89.95 @ OutletPC
Monitor Dell E2414H 24.0" Monitor $149.00 @ B&H
Prices include shipping, taxes, rebates, and discounts
Total (before mail-in rebates) $765.23
Mail-in rebates -$45.00
Total $720.23
Generated by PCPartPicker 2015-05-03 22:33 EDT-0400
/r/buildapc Thread