I'm still pretty devoted to Fallout (survival mode makes everything 100x more fun), but Skyrim is still way up there. Bethesda games have stolen my heart, but occasionally I'll throw some GTA or Saints Row in for kicks.
Just Cause is also great.
7 Days to Die is still in beta, but if you like minecraft-y zombie games, it's pretty good. Ark Evolved is beautiful and full of dinosaurs (instant love for that game) but gets very grindy. Shadow of Mordor still gets gametime from me too, really good for mindless carnage, and you can't go wrong with the LOTR universe.