I currently run multiple computers. They're all slightly on the old side and have been donated to me, and they all do just great at what I need from them.
First, I have a Dell PowerEdge T310 tower server, which is my home server with many services running on a Debian 11 Bullseye base with no GUI. This system has ECC RAM and has run consistently for me for up to about 60 days (and then the power flashed). Beside that is a PowerEdge T110 tower server also running Debian 11 Bullseye (with no GUI), and it simply provides more storage space for the main server as I so far haven't been able to get some higher capacity drives. This one was my main server for a few months, and was stable for easily 30 days and more even without ECC RAM. My daily use system is a Dell Alienware M17 laptop, running Debian 11 Bullseye. I used the Mate desktop environment for a while and just recently switched to the Cinnamon desktop environment. It doesn't get rebooted very often either, and because it's a laptop, power flashes don't affect it (although the battery isn't great so outtages do cause it to shut down).
All these systems (and more) are behind a Dell Optiplex 3010 running pfSense, which is complete routing and firewall software based on a customized version of FreeBSD.