Parts bought from eBay (because actual server level stuff is expensive when new). Still sticking with my personal theme of "OverKill isn't really a thing". Previous server incantations have all run Gentoo almost religiously since 2004, last year ('18) had some odd issues when updating that forced a reinstall that didn't seem to work so moved to Ubuntu server 16.04 LTS (18.04LTS was out, but would not work right with the SmartArray P800 raid cards that I had at the time - would see them, but they were not getting activated for some reason) so at least it was working, and haven't had the time to go back (yet) and figure out what went wrong/try again.
I generally have 5 or 6 instances of ARK: Survival Evolved running, for MineCraft I have 3 configured and running, also have Project Cars, Garry's Mod, PixARK, and Tower Unite servers as needed, with more being added as friends demand :P
Aesthetic goal is "it's not ugly" as it just sits in the basement next to the firewall system and cable modem. I do intend to eventually tape off and paint the front black - but as the drive cages are such a dark gray, I'm in no immediate hurry as you can't see much beyond the little bit with the handles.