I went through a FF stage and I played FFVII practically all day every day until I got to the end of the game where there weren't any save point, and once I got to that point I played it for over 24 hours straight till I beat it. I immediatley passed out after that though...
I also played FFVIII even MORE religiously than I did VII. It took much longer to beat though. But I remember playing it for a little under 24 hours one day. I still play it every once in a while, because theres so many things that you can miss on those games.