For fantasy, 13th Age is my go to; it’s all the good parts of 3E and 4E, updated to a more modern feel. Tried 5E, but it‘s too vanilla for me — doesn’t have much of an identity or an excitement factor. It’s just a genericlaly good version of D&D, an that’s no longer enough for me. With all the games that are out there now, games have to be more than just solid. They have to sparkle. 13th Age does.
Outside of fantasy, our group has gently migrated to Fate as the go-to system. First it was for genres ill-served by other systems (modern, mostly). Then we played a sci-fi campaign (Bulldogs) and I jumped back in with some Tim Powers - style adventuring in a weird version of 1838. Another player has started using Fate for Star Wars, and our current superhero campaign uses Icons, which is very Fate-influenced.
Not a concious decision; and we still okay other systems (Classic Deadlands, Numenéra, Call of Cthulhu), but Fate and 13th Age seem to do most of what we want.