I.e., games that hooked you in and you couldn’t stop playing until it was finished. Not games that just happened to be unexpectedly short. And by “completed” I guess I mean the main story etc, not 100%ing the game :).
For me, it would be Catherine, Bioshock Infinite and Black Mesa (although I think I got to the final area then had to go to sleep and complete it the next day). I also played an ungodly amount of Hades in one sitting, but didn’t get the “full” ending in one day.
Baldur’s Gate: Dark Alliance. Granted I had a lot less responsibilities back then but I thoroughly enjoyed the game.
Me and my friend used to play that a lot back in the day. It had a great co-op mode. Did you see it got re-released about a year and a half ago?