This is my primary home computer. I work from home, so most of the time it functions as a workstation, but in the evenings and on the weekends it turns into a quite capable gaming rig.
Display: Dell U3014
For work-related tasks I prefer using two monitors in pivot mode. However, since this rig is supposed to double as a gaming computer, vertical monitors would be quite impractical (I know, since in my older, work-only setup I have two 27-inch Dells). The 30-inch Dell U3014 is awesome as a gaming display, and provides plenty of screen real estate for my regular work-related activities. The colors are great, the screen is huge and I can't imagine going back to gaming on anything smaller.
Keyboard: Das Keyboard Model S Professional (Cherry MX Brown)
I'm really happy with this keyboard. The build quality is spectacular, and there's no comparing of typing on a mechanical keyboard to a regular rubber-dome one. I only wish those came in a wireless variant.
Speakers: CreativeLabs Gigaworks T40
I'm not an audiophile or anything like that, so most speakers sound pretty good to me. However, the difference between my old, cheap ones and those was quite noticeable. These speakers are pretty large, but they don't take up a lot of desk space because they are much taller than they are wide.
Mouse: Logitech Performance MX
Wireless, lasts a couple of weeks on a single charge, feels comfortable.
Gamepad: Xbox 360 Wireless Gamepad
Makes gaming in titles like Assassin's Creed or Watch Dogs much more fun. I was quite upset that it comes with non-rechargeable batteries and no charger whatsoever. I had to buy some after-market replacement with two rechargeable batteries. Now when one of them is empty, I just switch them and can continue playing without having to connect the pad to a USB cable or something similar. I highly recommend buying this gamepad if you play a lot of non RTS/strategy games.
Case: Corsair 350D
I originally planned to build this PC in mini-ITX form factor. Then I realized that if I do that, I'll have to keep the box on my desk, because it will be too small to turn on/off comfortably when it sits on the floor. That's why I went with micro-ATX.
Corsair 350D looks good, has plenty of space for cable routing and overall was pretty easy to build in (it's pretty large for a micro ATX case after all). It also has some nice extra features like toolless SSD drive slots. The only thing it's missing is a dust filter for the top fans.
Power Supply: Corsair RM 850W
This is a semi-passive PSU, which means that under normal load it doesn't use its fan, only when over 50% capacity. It has pretty hard cables which don't bend easily, so cable management wasn't as simple as it could be, but I wouldn't count that as much of a con. It has modular cabling and Gold efficiency rating to boot.
CPU: Intel Core i7-4770K
I can't believe this one is already a previous generation CPU;) I chose this part because it offered top of the line performance in micro ATX form factor.
I tried overclocking it, but I couldn't find a stable overclock. I could get firstname.lastname@example.orgV running for a couple of hours in Prime95, but I didn't find a combination of settings that would last overnight and after a week or so of trying I finally gave up. My mobo already overclocks it to run at 3.9 on all cores in Turbo mode, and for now that's all I need.
I'm a bit disappointed with how badly my CPU sample overclocks. If I expected that, I would probably buy a cheaper cooler.
Motherboard: Asus Maximus VI Gene
I originally bought a Xonar DX sound card for this build, but after listening to both the integrated audio and the discrete sound card I decided to move that card to an older build of mine, where it would make a much bigger difference. The sound quality is really quite good (perceptibly better than in my old rig), and to my ears the differences between the integrated and discrete audio were way smaller, than between different sets of speakers. There are some other bells and whistles here, like a mPCIE extension slot, but I haven't used it.
RAM: Kingston Beast 32GB
If it looks like an overkill, that's because it is. As of now, I can easily get by with 16G of RAM (the RAM usage tops out at about 12-13G with a couple of VMs running). However, I have never owned a computer where I didn't end up maxing out the RAM at some point in time, and I figure that since DDR4 is on the horizon, I can save myself some hassle 2-3 years from now by buying the extra RAM ahead of time. While I'm not using it, I can still run a RAM disk on what I don't need.
GPU: GeForce GTX 780 Ti
I didn't want to spend this much on a GPU (it cost around $800), but with 2560x1600 screen resolution, even this card is not enough to max out all the settings in titles like Assasin's Creed 4 or Watch Dogs. With micro-ATX form factor SLI wasn't an option (at least as long as I need at least one other expansion slot) and even if it was, my budget allowed at best for dual GTX 770, and those would only have 2GB or VRAM per card, so no high-res texture packs for you!.
I picked the version of the card with stock cooler because I thought that a blower-style cooler would be better for the thermals and I don't mind the little extra noise when gaming, especially since I usually play at night with my headphones on.
Storage: Crucial M500 480GB and WD Red 2TB
M500 might not be the fastest SSD around, but I know from experience that the performance differences between SSDs are mostly theoretical, so I didn't care about a few dozen Mb/s as much as the $/GB ratio, and M500 was definitely the top choice for that. The mechanical storage is mostly for stuff like movies, and WD Red is fast enough and big enough for my needs.
Cooling: Corsair H100i
I bought this cooler mostly with overclocking in mind, but that didn't work out so far. I hoped to install in in pull configuration on the top of the case (to make cleaning easier), but the screws included in the kit were too short for that. I replaced the stock fans with Noctua NF-F12s, which run pretty quiet and seem to do a good-enough job overall.
Case fans: Noctua NF-A14 and NF-P12
The P12 is used as a rear exhaust and the two A14s are used as front intake. Most of the time they are practically inaudible, but they can ramp up a bit when doing things like stress testing the CPU. Under no circumstance are they ever emitting any unpleasant noise, so I'm quite happy with the set up.
Were I to build this computer again, I would probably skip buying the expensive fans though. They almost never need to run at higher RPM under normal operation, and the only time they need to do that is when I'm gaming and have headphones on. I could have saved some money by buying cheaper, louder fans (or maybe even keeping the stock ones).
Wi-Fi card: TP-Link TL-WDN4800
I originally bought an ASUS PCE-AC66 card for this build. Unfortunately, it turned out that that particular model does not work with the Z87 chipset (it works with Z77 just fine), so I had to exchange it. This one does not support the new AC standard, but it cost half as much as the other one and it works, so it has all I need for now.
Chair: Steelcase Leap v1 (reupholstered)
Very comfortable and ergonomic chair. It's pretty high (which makes a difference for my desk). I especially like the soft cushions, which make it much more comfy than the Aeron which I previously had in the office.