TL;DR Most of the parts here, I bought from a friend who upgraded to a 6600K and GTX 670. Hence the super low price of them all. This is primarily a gaming machine and something to keep me occupied while I get the cash for a Polaris GPU and later on, Zen CPU.
CPU: Got this Athlon X4 760K on the cheap. As we all know what AMD processors lack in instructions-per-clock they make up for in core count. Unfortunately my most frequently played games are CPU heavy, such as Planetside 2 and Skyrim. While I stay above 30 FPS in most situations I am definitely disappointed.
Cooler: Cryorig H7. This was $35 total off Amazon. Keeps the 100W Athlon nice and cool and generates next to no noise on default fan speeds. I use a CM Sickleflow 120 on the rear as a kind of pseudo-exhaust fan since I have no mounting hardware for the Sickleflow to go on the case.
Board: MSI A78M-E35. Keeps my parts together and the Athlon X4 760K at 4.4 GHz. We'll see how long it takes to vaporize itself.
Memory: RAM is fairly simple, just two 4 GB sticks of DDR3-1866. Never exceeded 6.6 GB of RAM usage so no plans to upgrade until Zen.
Storage: The only excuse I have for this is that it was $10. Debating between a 240GB SP550 SSD or 1 TB Caviar Blue HDD.
GPU: GTX 660. This was used on Amazon for $80. Replaced its thermal paste with the CP7 that was included with my H7 and I've seen about a 3 degrees celsius improvement in temps on identical loads and fanspeeds. Playing Overwatch on Medium-High and 80 FPS, Planetside on similar settings and 60 FPS though I have a CPU bottleneck in that game.
Case: Picked up from a recent Newegg sale for a whopping $43. My first choice would have been the Deepcool Tesseract (I prefer blue and better CPU cooler clearance) but I couldn't pass this up having already used one to build a friend's PC. Cable management is doable with a non-modular power suppply but I wish it was color-neutral and included some more fans and better cooler clearance.
Power Supply: Relatively loud and ugly 600W Thermaltake non-modular power supply with ketchup-and-mustard wires. But it was cheap and wasn't DOA like the EVGA NEX750 I ordered.