I just played Xonotic for the first time ever and now I'm interested. I like a game I can be sure isn't selling my data to China.
I would personally like an RTS, a game in whatever genre Stick Fight falls under, and sandboxes, although any genre is fine. I don't contribute code, but I'm pretty good at finding bugs, etc. and get a few laughs out of people on the forums with my jokes.
Games in early development preferable, mostly for the active community these tend to have, so I can share less formal work with them and join their Matrix.org room or something
Dwarf Fortress isn’t open source but they sure as hell aren’t selling your data. It’s probably my favorite game of all time, but it’s not exactly easy to dive into.
IIRC the creator claimed it will be made open source when he dies, provided there isn't evidence of foul play. Great game either way.
I wonder if that will still be the case now that the game is pending a Steam release. The free version will continue onward, so presumably that will become FOSS someday.