Debian, Ubuntu and Fedora should be good (in that order); I'm not very aware on truenas to give an opinion, but it seems it will work just as well from other comments.
I personally use Fedora, and it's been a solid experience too, with the only gripe bring SELinux. I required a fix for SELinux, but it has worked flawlessly since.
However SELinux might make it annoying to work with containers, so you could consider either switching it off, using another distro or using appropriate configurations to work with it correctly.
Photography - added benefit is that you will usually go out for this
Music - an instrument is good
Drawing/Painting
Programming (hit or miss, I found learning unity was fun)
Video making - recording video games playthroughs, cooking, and so on.
Finally, one that usually everyone probably also may mention - Therapy - not a hobby but having to be able to talk about it is often good
This is of course not an exhaustive list - but it depends on what your interests are. Hope this is a good pointer to what you're looking for.