Edit: And in the end, it's back to good old Fedora with Xfce. I guess I'm an old man, fixed in my ways. Haiku was interesting, but not nearly as stable as needed. OpenSuSE with Xfce was rough, it requires more polish.
I've been a Fedora Linux user for a million years by now, and I haven't touched any other OS (outside of Windows 10 and 11 at work).
Lately I got a refurbished ThinkCentre from ca 2018 (7th generation Intel i5, 16GB RAM, Intel HD 630). The initial idea was to use it as a media PC but the small form factor ended up not being small enough for my living room.
Now I'm thinking of using it as a desktop PC for a while, to see if it can make my laptop be a portable machine again instead of always plugged, always on. If it doesn't work out, I'll use it as a home server.
Since this is all an experiment, I want to give a new OS a shot before I settle for the familiar Fedora.
OpenSuSE is the first on my list, but even from the LiveUSB I noticed that the software selection is more limited than I'm used to.
I'm thinking of giving HaikuOS a shot as well.
What else has been going on in the world of free OSes since 2007? What's one that you are excited about?
If you're looking to try something a little different, I recommend Guix.
It's based around a nyx-style package manager written in scheme, which is also called guix. There's an EDSL for writing package definitions. One interesting result about this is that the package manager has a REPL and a dedicated emacs mode
Instead of systemd, the PID1 process is called GNU Shepherd, and is also written in scheme.
Guix also has a strong emphasis on bootstrapping. You can build almost the entire system from source, relying on only a few binaries to start with.