My computer sits in the original CoolerMaster Stacker case with the side cover off, in a 3x5 cabinet built into the attic of my 1/2 story second floor. 8" window fans (one now broken) ventilate it from the attic side on days when heat becomes an issue.
The internals are a Skylake 6500K, 16 GB RAM, an EVGA 1080 FTW, a 512GB Samsung 950 Pro M.2 boot drive, a Samsung 850 EVO 512 GB SATA, and a Soundblaster Z. It runs Windows 10 Pro and occasionally other guest OSes to play with. I am looking forward to dinking around with Ubuntu desktop on it, but not enough to install the fast ring.
I browse on Firefox with ABP, Media Player Classic for media, PDF X-change for PDFs, Office 2007 with macros etc disabled (only because my wife owns a Home and Student copy and I almost exclusively work with only basic files of my own creation, otherwise it would be Libre Office) Search Everything because I can't be arsed to do chores while waiting for searches.
This feeds to my sit/stand/treadmill desk which I made out of a DIY Uplift motorized base and a recycled interior door as the table top, with leftover laminate flooring as the top surface. On the desk are an Acer XB270HU IPS 1440p G-Sync 27"' monitor as primary, and, for now, a BenQ XL2410TX in portrait mode. It was previously my main monitor and replaced a SOYO Topaz S that exhibited ever more frequent image corruption. I use a CM Storm Quickfire Rapid tenkeyless keyboard, a $15 gaming mouse that tracks exactly as I expect, and an Oculus Rift with a Razer Hydra that I bought years and years ago on Woot for around $80. Also, no money to buy VR games because I blew this year's discretionary funds on this system.