I built my first computer in 2003 (with a socket 478 P4 3.2GHz and a GeForce FX 5950 -- had to be ready for HL2) and I've been addicted ever since. Below is the computer setup I started in 2009; since then, almost every part has been replaced at least once. The internals are listed a bit farther down the page.
This display setup is commonly called a "portrait-landscape-portrait" (PLP) setup and, with these monitors, I have a total resolution of 4960x1600. Getting games to work across all 3 monitors can be a chore (nVidia Surround and AMD Eyefinity don't work with mixed monitor orientations), but is usually possible with some combination of SoftTH, BWin, Flawless Widescreen, ShiftWindow, and ini editing.
I recently bought a 42U Dell server rack cabinet from craigslist and moved my primary desktop's guts into a rackmount chassis. Currently, I have my desktop, FreeNAS server, its UPS, and my home network equipment in the rack. I have a couple more builds in mind in the future, including a Linux VM host and a Hackintosh machine that will also go in the rack.
In the past, I've always used headphones for audio. The HD595's are very comfortable and sound great when paired with the tiny PA2v2. Recently, however, I picked up a set of KEF LS50 speakers and I've really been enjoying them. The receiver is pretty old and doesn't have any HDMI ports, so I only run audio through it, with my desktop, my laptop, and my cell phone as the only sources (desktop via digital coax, laptop and phone via analog RCA). I have my headphone amp connected to the preamp out so I can switch between speakers and headphones easily. I currently have my headphones set up as a headset (hence having my phone as an input on my receiver) with a ModMic both for gaming and for business calls. It's maybe a bit overly-complicated, but very comfortable for gaming and longer phone calls.
I've had the Ikea Bekant desks for a few years now and I'm pretty happy with them. I would have preferred the Galant, but they discontinued it a few months before I purchased. While I'm happy with the Bekant, I wish they had more of a selection of different sizes that matched up together like the Galant did, though. For reference (an overly-detailed reference; I couldn't find any of this info online when I was planning), there are 5 different desk shapes for the Bekant: a 55"x24" rectangular, a 63"x31" rectangular, the two "L" shape corner desks, and the 5-sided. On the corner desks, the ends of each side of the "L" are different lengths: ~20" on the short side and ~24" on the long side. Obviously, only the end on the longer side will match up with a rectangular desk (the 55"x24"). However, with this combination, you would end up with a really long desk (nearly 10 feet) with a stubby little foot on the "L" (43"). The only mate for the short side of the "L" desks is the 5-sided desk, which is ~20" on the right side and ~24" on the left. The problem is, they only make one version of the 5-sided desk, so if you want use it with the right-hand corner desk, you have to have the pointy side facing away. This really leaves you with only one option for a large corner desk, which is the configuration I have here. Having the little pointy end on the 5-sided desk off to my left isn't bad at all, but the right foot of the 5-sided desk does get in the way sometimes (you can see in the pic that it goes perpendicular out from the wall). Unfortunately, there aren't any options for mounting the leg differently as the metal base is pre-cut, and it would likely be unstable mounted any other way. One day, I would like to build a custom desk, but the Ikea setup works well for now.
I built the file server in October 2016. I have an extensive writeup on it here, but to summarize: The server is running on FreeNAS 9.10 with 2 8-drive RAID-Z2 arrays: one array with 8TB WD Red drives and one with 4TB WD Red drives for a total of ~60TB of usable space. The drives are connected to 2 IBM M1015 cards which I re-flashed to run in IT mode. The boot volume is stored on 2 Intel 540s 120GB SSDs in RAID 1. The server is housed in a SuperMicro SC846 chassis with two 920W redundant PSUs. The system is built on a SuperMicro X10SRL-F LGA2011-v3 motherboard. I’m using an Intel Xeon E5-1630v3 CPU (4 cores/8 threads @ 3.7GHz) and 4 modules of 16GB DDR4 Samsung ECC/registered memory for a total of 64GB of RAM. I’m using a Noctua cooler on the CPU and I replaced the noisy stock chassis fans with quieter Noctua fans. I got an APC 1500VA Smart-UPS to deal with the relatively frequent power outages in the area.
I set my primary dataset with recordsize = 1MiB to account for data block placement in an 8-drive Z2 array. All the data is shared via SMB/CIFS. The system hosts about ten Debian-based bhyve VMs to run various services I use on a day-to-day basis (including nginx, pi-hole, an OpenVPN server, and an rclone client I use to back up my data to the cloud). I have scripts set up to send SMART and zpool status reports to my email address on a weekly basis and scrubs/SMART checks scheduled every 2 weeks. I also have a script that automatically adjust the chassis fan speeds based on live HDD and CPU temps. Some photos of the server are below.
Rack Cabinet - Front
Top to bottom: Network equipment, desktop, server, CentOS MBP (hosting Nagios), UPS for server
Rack Cabinet - Back
It's not the neatest wiring job, but it works and it's still relatively easy to work on. As I mentioned above, almost everything in here has been swapped out at least once since I originally put the machine together in 2009. The CPU started out an i7-975, but I got an engineering sample i7-990x and sold the 975 on eBay. I originally had a pair of GTX 260s in SLI, then swapped one for a used GTX 480, then swapped them both for a GTX 690, and finally swapped it for a GTX 1080. I also had a GTX 610 in there for my TV, but it was causing so many issues that I had to remove it (the banner picture on this page is that very GTX 610 with the heatsink removed, doing more good than it ever did while inside my computer). I swapped out the original 12GB of Corsair RAM I had installed for 24GB of Kingston HyperX because I was running out of memory during heavy Photoshop/Lightroom work. I'll eventually part out this machine and rebuild from scratch in a rackmount case, maybe in a couple years when 120Hz (or even 240Hz) 4K monitors aren't absurdly expensive (and a pair of GPUs exist that can drive 3 of them).
Data storage is a special passion of mine. I currently have a bit over 73TB of usable space (excluding my boot drive), 70TB of which is redundant. As I mentioned above, I recently built a FreeNAS based file server, which makes up the bulk of my total storage.