I built a computer back in 1999 towards the end of college just to try it. It was a regular computer with an AMD processor, 8 Gigs of ram and 250 GB of Hard drive space. It was pretty powerful in the day where DOOM occupied our time over THE MAINFRAME NETWORK at UCONN...yes, we played over a mainframe/intranet. It did not work perfectly (inconsistencies between the motherboard and processor), but it was good enough for the time. I shut it down in 2002 when I went to a MacBook Pro.
Looking to break away from console gaming and cut the cord for cable, I decided to get a steam machine. Looking at the price and limitations of what was out there including the ability to upgrade, I decided to try to build a small form factor entertainment computer for gaming, streaming services, and for editing RAW files and 4K movies from my Sony A7iii. Needless to say I did a lot of web searching for a small volume case and miniature motherboard and graphics card. Everything else would be built around this.
That being said, I found a lot of good reviews regarding the Silverstone SG13 which was compatible with Mini ITX Motherboards and Mini GPUs. Looking for higher end components, I went with the Asus ROG Strix Z370-i Gaming motherboard with the tried and true Intel Core i5-8600K processor and used the low profile Noctua NH-L12S CPU cooler. I thru in 2 x 8GB Corsair Vengeance RAM and the Samsung 60 EVO 500GB M.2 SSD onto the board. This SSD is purely for running Windows 10 Home (I really wanted to go Linux, but wanting to use the rig for multiple entertainment purposes and compatibility issues I went back to MS).
Due to the limitations of a 10.5" GPU, my search led me to the Zotac - GeForce GTX1080 TI Mini which is more than enough for the gaming I am planning as well as my photo editing needs.
For storage, I went with a Hybrid Hard drive, the Seagate FireCuda 2TB 2.5". I purchased three of these (and modified one of the spare brackets in the SG13 to mount the 3rd drive which works perfectly. I currently have one for Gaming, one for media (Photos/Videos) and one set up for entertainment (primarily for recording purposes when I cut the cord).
I threw a 120mm Rosweill Low Profile fan as the intake, bought a Logitech G Pro Keyboard, hooked up a Logitech G600 Gaming Mouse I have had for years, and put a secondary Logitech M570 for daily activities.
To allow expansion in the future, I am running this rig with a Corsair SF 600W 80+ PSU.
To top it off, I added a Asus 27" ROG SWIFT 2560x1440 @160Hz Monitor which is great for gaming and perfect for photo and video editing, even for 4K. With total compatibility with the motherboard, G-Sync works flawlessly.
I also bought a USB switch which I have my keyboard and mice connected to which allows two devices to be used. When needed, I plug the HDMI and the second USB connectors to a laptop, hit the switch, and all the peripherals and the Monitor can be used.
Overall, it might not be the prettiest build with the case, but it checks off everything I need for work and play, is expandable/customizable, and should be powerful enough to handle most if not all games for the next few years.