I had originally built this in a much larger full tower case, with a Gigabyte Motherboard, and with a GTX 780. I have just recently swapped all of those parts out with these ones and thought it would be a good time to post a few pictures here. I currently only have access to the camera on an HTC One (which is fairly mediocre) so hopefully I can update this withe better pictures in the future.
I use this build mostly for playing games, specifically Battlefield 4, DotA2, Skyrim (with plenty of mods), and various other Steam games. Currently I game on a 1080p 60Hz monitor, which the 980 is massively overkill for, but I expect to be upgrading to an ROG Swift (or hopefully something similar with an IPS display) sometime in the future. Currently I can completely max any game I try at >60fps.
Anyway, here are the justifications for all my part choices:
CPU: i5 4690k I went with this because it is basically the best CPU for gaming currently. Once overclocked, the 4690k will beat out any AMD FX chips and match or beat the performance of any i7 in games (I believe). Since I am not a streamer or a heavy multitasker, I felt no need to spend any extra for hyper threading on an i7. Unfortunately I seem to have gotten a pretty poor overclocker, because no matter what I try, I can't push my 4690k past 4.3 GHz. I've decided to keep it running at 4.2 GHz, which I can do without turning the voltage up too much.
CPU Cooler: Cooler Master Nepton 280L This is one of the best performing all in one water coolers around with its 280mm radiator, and I was able to find it on sale for less than $100, so it seemed like a great choice. I understand that something like a Noctua NH-D14 would have been a better value in terms of cooling/dollar, but I much prefer the aesthetics and ease of installation of AIO's, and most 280mm AIO's do still seem to perform a little better than the best air coolers.
RAM: Adata XPG V2 It was cheap, well reviewed, and didn't mess with my color scheme. That's basically it lol. I don't really ever use more than 8GB when gaming or anything else, so I didn't feel the need to go for a 16GB kit.
SSD: Kingston V300 SSDNow I understand that this isn't the greatest SSD I could have chosen. It will probably be something I upgrade pretty soon. Nevertheless, it was very cheap at the time I bought it and it's fast enough to keep me happy with the price I paid for it.
GPU: EVGA GTX 980 Originally I had built this system with an EVGA GTX 780 FTW because it seemed to be a pretty good value at the time (and because I'm a fan of Nvidia). However, about a month after I purchased it, the 980 was announced. Luckily, EVGA's step up program allowed me to trade my 780 in for a 980 without having to pay much more than the shipping costs. The 980 does get me decently higher framerates in games than the 780 did. I should be putting it to good use soon with a 1440p/144Hz monitor.
Case: NZXT H440 I really like the look of this case, and it's built very well. It's a mid tower, yet it has room for a second GPU if I wanted to add one and for multiple radiators if I wanted to do custom water cooling in the future. Very happy with the H440.
PSU: EVGA Nex 650G 650W was really all I needed, and this was fully modular, had black sleeved cables, and built by respected manufacturer for a decent price.
The peripherals I'm currently using are the Logitech G502 gaming mouse, Logitech's cloth mousepad, the Cooler Master Quickfire Ultimate mechanical keyboard with Cherry MX Blue switches, and the Sennheiser G4me Zero headset.