I'm a very competitive individual, so when someone tried telling me I couldn't build a PC significantly better than his XBone for under $500, I decided to try my damnedest. I already swapped out the PSU for a 750W and the case for a Corsair 780T I had laying around, but this is the initial build. All the parts were found on either /r/hardwareswap or the Columbus Craigslist. I'll add on some of the results of my testing for this rig, each test was 2 hours of actual gameplay, not just random benchmarks, so it's actually good info. My next plans are replacing the mobo with a Sabertooth X58 (current board has major voltage droop holy hell. 1.28V in the BIOS nets me 1.2V in CPU at full load) and maybe a Xeon Upgrade, with an H115i for sure. Maybe even a second 7970.
The bench FPS results are:
Overwatch, Ultra Preset: Min: 10 Max: 156 Avg: 85
Bioshock Infinite, Ultra Preset: Min: 26 Max: 213 Avg: 72
Tomb Raider 2013, Ultimate Preset: Min: 42 Max: 78 Avg: 60
Rise Of The Tomb Raider, Medium Preset (Soviet Installation and Geothermal Valley are the culprits...), DX11 (DX12 had very weird flickers): Min: 9 Max: 145 Avg: 61
Shadow Of Mordor, Ultra: Min: 30 Max: 252 Avg: 58
Rocket League, Ultra: Min: 130 Max: 250 Avg: 200
Basically, it's a very capable rig. I currently use it as a plex server and so that when a buddy or girlfriend come over they can game on it instead of bringing over a PC.
The MSRP of the parts when they were released all totaled $1,599, and I paid $335, for a difference of $1,264. I started this project before the RX 480 came out, but this will still beat most brand new PC's under $500 in the CPU department.
I also added a 1TB WD Red I had sitting in my main PC that was holding my movies and music.