games that you've played for more than 12 hours straight

[Yuzzi]

Team Buddies. Damn I'm unique. (There are probably other games I've played for 12 hours straight, but that's all I can be sure of.)

 

[Skutch]

Final Fantasy VII, Final Fantasy Tactics, Final Fantasy XI, Parasite Eve, Fallout 2, MechWarrior 3, Team Fortress 2, Left 4 Dead

 

[Zukonub]

Super Mario Galaxy, I think, I'd played for nearly 15 hours before getting so tired that all of the Nintendo Hard levels made me genuinely want to kill myself.
In Final Fantasy XII, I once spent nigh on 13 hours just doing side quests and shit, training my lesser party members as well. The last three hours, unfortunately, were spent on Yiazmat, and, as all of you who've played the game should know, I failed.

 

[soren7550]

Might have done that for Mass Effect, The Orange Box, BioShock and maybe Assassin's Creed.