I've always been good at staying awake when I'm excited about something. xD

It's basically tradition that I play a new KH game from start to finish and don't fall asleep until the looping piano piece after the credits. <3

You know, I actually can't remember. I'm sure I've had some 8 hour sessions before, once upon a time, but I can't tell you what game I was playing. Recently, I'm lucky to get two hours in before I get bored. No matter the game.

12-14 hours with Ocarina of Time.
When I had time... ;_;

last time i spend all day playing, the game was xenoblade.
20 hours.

Got Uncharted Dual Pack for the Ps3 to get ready for Uncharted 3. Passed them both in one go, I did 12-20 hours easily.

Arround 22-23 hours Wing Commander 3.

A long time ago in a galaxy far far less digital.

I think it was 12 ours on yu-gi-oh Duel Academy, from GBA. There was also a similarly long play session of Super Mario Kart (snes) battle mode.

Around 12hours, maybe slightly more. Playing Warcraft3, done it also playing World of Warcraft.

I wont tell you which game, but several years ago I played a certain game for 15 hours.

edit: All I'll say is that it's an MMORPG

Disgaea on PS2 - 14 hours on a Saturday - Much of this was post end game grinding in item world type play. Even had a map memorized to do quick leveling of certain classes. Crazy part is after 200 hours I still did not 100% it.