If I can have Immortal Empires with all of the DLC, that’s my choice, too. Ever since the first TW:W came out I’ve always had one installed on my SSD. Usually, I install a game, play it, then uninstall it, but TW:W, I keep installed. It’s what I play between other games, and I never grow tired of it.
Dwarf Fortress is a great call, I haven’t kept up with it in a long time though. I know it was always playable, but is it actually done now? If not I would pick a more classic roguelike like ADOM or tales of maj’eyal.
Dwarf Fortress got a graphic upgrade about a year ago. It is much more approachable now but it’s still Dwarf Fortress under the hood (so “approachable” is relative).
I find RimWorld more accessible but if you had only one game to play for the rest of your life Dwarf Fortress might be better.