23 might actually be my longest. When I do my overnight gaming sessions, anything goes, and I've largely stopped drinking, so that has made things shoot into the stratosphere.
I used to routinely sit down with a bottle of scotch or other booze and play until the bottle was gone. Usually 7-12 hours, depending on how voracious I was into either the drinking or playing aspect. I did many a-nights of WoW like that, in particular, since you don't have to be sober to grind. Fuck, you shouldn't be sober for grind sessions.
Let's see, I logged over 80 hours into Blue Dragon over 6 play sessions, not counting one brief 4-5 hour one. That doesn't count. At least 3 of those sessions were between 12 and 20 hours, on weekends. Eternal Sonata was like 40ish hours in the space of one full week, Over 4 or 5 sessions. That was right after BD so I was taking it easy.
Back in high school, I beat Final Fantasy 7 in 3 days, with a clock time of a lil' over 30 hours, although I don't recall specifics. And I didn't miss any school during it, either. That's not including the Gold Chocobo. I went and did that leisurely only after I had beaten the game. Same for the optional weapons.
