I have HoloISO running around on mini PCs because they just work as remote steam machines, can play games in their own right, and I can use them as media boxes if I want. I don't necessarily recommend it, but it was super easy to install and configure except for the Bluetooth issue that cropped up occasionally where I had to unload and reload the Bluetooth module. Now I just have a script that automatically does that on boot because I can't give a shit about fixing it.

I also have a couple of Slax USBs running around. They used to be relatively popular with folks who fixed computers. I like building from modules and I'm familiar with Slackware so it was a good fit for a live environment.

Rhino Linux! A rolling release Ubuntu distribution. It uses the Ubuntu devel repos + pacstall.

Is Alpine Linux obscure? Well, using it as a desktop is obscure, I guess. The decision to use musl libc is the main limiting factor for desktop usage, but thanks to the existence of runtime package managers like flatpak and/or static linking, you can run basically anything that requires glibc on Alpine these days (at the expense of extra disk usage for glibc libs).

If you don't know much about Alpine, it is an extremely lightweight Linux distro designed primarily for containers and virtualization, that ships with busybox and musl libc. It's basically the closest you can get to GNU/Linux without the GNU. The main appeal to me is the simplicity of the tooling and installation, it's the only Linux distribution I've used that gives me a similar vibe to OpenBSD. The defaults are almost perfect, but the first thing I would do when installing it is install the docs metapackage (otherwise you have no manpages), and optionally replace busybox with coreutils and friends (personally can't stand how non-posix compliant busybox is). I'd also replace the default busybox ash shell with a nice kornlike such as oksh, a clone of the OpenBSD shell.