Factorio.
Utterly, unhealthily obsessed, and no end in sight.
It's good for me because the focus is building, with some defensive combat on the side; I've tried Mindustry to try to get the same time sink on my phone, and I've learned that I don't like tower-defense style games; but civilization building (-like) is addictive.
Excellent game, runs like a dream on Linix. Lots of fun.
Is there anyone who's tried Factorio who doesn't like it? I haven't come across a Factorio rant yet.