AOE2 (Age of Empires 2) is _still_ going strong some twenty years later. Active reddit, youtube, and twitch communities. Still releasing new civ expansions on Steam. I think it's success is due to just how balanced the game is. It's like a really fast moving chess game.

I like factorio as well, but honestly it started to feel like work after I got the hang of it (needing to refactor etc).