For me it would have to be this little f2p mmo called Dream of Mirror Online. I had a 46-hour leveling fest on there once. Aside from that it would have to be Legend of Zelda: Breath of the Wild when it first came out. Played 13 1/2 hours solid during the release day, then went on to total around 72 hours during the first week (while working part time, mind you).
My binges are few and far between but when I fall into a game I can get lost in that world for a long time.
My binges are few and far between but when I fall into a game I can get lost in that world for a long time.