Probably some 6 hours? On some RPG most likely. I really doubt it was more than 6 hours. Maybe 8 when I was really young and on vacation...

12 hours with Sunset overdrive

Either Bayonetta 2 or Wind Waker HD. I'm pretty sure I spent around 15 hours playing them in one session.

I think the thing that can help you the most in making long sessions is having a goal. Like, if you can see the game ending soon or if you see that getting the platinum for the game is very close. I don't think I've ever gotten a platinum while not in a 6+ hour session.

I think about 13 hours.

Near the end of it I was so disillusioned, my mind was still stuck in the game. While trying to sleep I could still see myself playing the game.

My buddy and I went well past the 24 hour mark playing a game of Hearts of Iron III (he was Germany I was Italy)... It was probably about 30 hours with plenty of caffeine and the remnants of adderal in our systems.

That's an anomaly, though, I swear! Lol

Dark Souls - 5 hours

never more than 10 hours , it was on assassin's creed (2 or brotherhood , i don't remember) and close to that on skyrim
i did 8 hours when i was much younger on prince of persia (the two towers) , and now i miss the prince days :(

Edit : i know it is not gaming but i spent more than 24 on watching anime  (300 episode of one piece , 250 of bleach , 200 of Gintama , ofc not the 3 at the same time) 

I honestly don't remember. I'm not on the PS3 so much anymore. I remember being 14-15 hours with a game, but don't remember which. Peace Walker, Fallout 3, GTA IV... I have no idea of which.

The only game i have gone beyond 10 hours , is the civilization game series my record is 16 hours I think.
It's very time consuming to try dominate the world. :P