My most frequent return game has been The Elder Scrolls: Daggerfall. Frankly, I'm shocked that Bethesda of all fucking companies still allows me to download it for free but more importantly, they (sort of) allow modders to basically remake the game in Unity. It's at a point now where Daggerfall has never been more beautiful and - more importantly - STABLE, God knows Bethesda aren't the best coders in the world. I guess I'm lucky in that sense. but I am always in fear of the collapse of Steam as well as the abandonment of games...