rstoledo :
Being really honest about it, I believe this will fall into the "Do whatever you like" category, both should handle all of those games pretty well an therefore it depends on what else are you planning to get.
I believe that going for the FX6300 is the best option (currently, one of the best value-performance you might find), and going for an GTX 760 or the R9 270X instead of the GTX660 would provide a better gaming performance to you.
Was looking at neweeg for prices comparison, the same 80 bucks that would upgrade it to the 8350 would get the GTX660 to the GTX760, for the intel option (the locked 3570), it will be 10 bucks more than the amd solution... That and the mb price that you havent settled yet...
CPU Intel Core i5-3570 3.4GHz Quad-Core $208.97
Motherboard ASRock Z77 Pro3 ATX LGA1155 $95.66
Memory G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1866 $84.99
Storage Western Digital Caviar Blue 1TB 3.5" 7200RPM $59.66
Video Card Asus GeForce GTX 660 2GB $179.99
Wireless Network Adapter Rosewill RNX-N250PCe 802.11b/g/n PCI-Express x1 $15.99
Case Corsair 200R ATX Mid Tower $49.99
Power Supply Corsair 600W ATX12V $54.99
Optical Drive LG GH24NSB0 DVD/CD Writer $15.99
Operating System Microsoft Windows 8.1 - 64-bit - OEM (64-bit) $99.98
Total: $866.21
CPU AMD FX-8350 4.0GHz 8-Core $194.67
Motherboard Asus M5A97 LE R2.0 ATX AM3+ $71.98
Memory G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1866 $84.99
Storage Western Digital Caviar Blue 1TB 3.5" 7200RPM $59.66
Video Card Asus GeForce GTX 660 2GB $179.99
Wireless Network Adapter Rosewill RNX-N250PCe 802.11b/g/n PCI-Express x1 $15.99
Case Corsair 200R ATX Mid Tower $49.99
Power Supply Corsair 600W ATX12V $54.99
Optical Drive LG GH24NSB0 DVD/CD Writer $15.99
Operating System Microsoft Windows 8.1 - 64-bit - OEM (64-bit) $99.98
Total: $828.23
Are these okay?