Hello, I am 14, and this is my first build in which I decided to join the master race. I had planned this build for about 6 months before buying it. I have had it for about a month now and no problems so far. The computer itself (not including peripherals) cost around $800 including Windows 8.1.
CPU: I originally was going to settle with the fx-6300 but found a bundle deal with my motherboard at Micro Center which was actually cheaper than buying the fx-6300. This is a very solid CPU with 8 cores and very fast at multitasking. When I briefly overclocked it in the BIOS I got around 3762MHz overclock because with a higher overclock Windows refuses to boot up. Your mileage may vary.
CPU Cooler: Keeps the CPU nice and cool during long gaming sessions. The stock fan gets loud at higher RPMs which is why I bought a replacement 92mm fan. Not much else to say.
GPU: I was planning on buying the R9 280, but settled with the R9 270x because of budget. All games run great at maxed or just under maxed (Battlefield 4 can run on ultra but gets the occasional drop in frames.) It runs quiet and have no complaints. I also plan on running crossfire in the future when I have more money. When overclocking it gets a little toasty but not too bad.
Motherboard: I bought it because it was part of the CPU bundle deal. Does what it needs to do. Only complaint is that the USB 3.0 connector is on the complete opposite side of the board from the IO panel. If the USB 3.0 cord was an inch shorter it wouldn't have fit.
Case: It looks good, has a nice window, does its job. Cable managing was a bit tight and the only reason I could actually close the back panel is because the cables are flat on the power supply. Definitely still worth buying.
The reasons I bought the other parts aren't really worth mentioning, basically "It works and looks good."
Feel free to add recommendations for parts and I encourage all constructive criticism. Also feel free to ask questions, you know I have it sitting here right beside me so answering them isn't that hard.