Is this a good gaming PC?

numanator

Honorable
While I am here, here is a decent build for $850, i5, gtx 770, No Overclocking, No OS:

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: Intel Core i5-4670 3.4GHz Quad-Core Processor ($204.99 @ Amazon)
Motherboard: Gigabyte GA-H87-D3H ATX LGA1150 Motherboard ($101.39 @ Mwave)
Memory: G.Skill Ares Series 8GB (2 x 4GB) DDR3-1600 Memory ($64.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($49.99 @ Amazon)
Video Card: MSI GeForce GTX 770 2GB Video Card ($319.99 @ Amazon)
Case: Cooler Master HAF 912 ATX Mid Tower Case ($49.99 @ Newegg)
Power Supply: XFX 550W 80+ Bronze Certified ATX Power Supply ($49.99 @ NCIX US)
Total: $841.33
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-04-18 02:15 EDT-0400)
 
Hmm FX-8320 - OK, MSI 970A-G46 (AM3+) - OK, G Skill 2 x 4GB 1600 - OK, Barracuda 1TB - OK, XFX R9 270X - OK perhaps Sapphire would be better, Rosewill Mid Tower - very nice, EVGA 500W - OK but I'd rather XFX, Corsair or Seasonic - costs twice as much but won't let you down and Windows 7 - good. Maybe adda a CPU cooler - say Coolermaster Hyper 212 EVO - very popular here.

Personally I like Intel better than AMD so I'd go with numanator's CPU and mobo. I also like his 770 and XFX. Just about any case is fine by me as long as its an ATX and big enough to fit your cooler and graphics cards.