24 hours. One game.

[Omnific One]

Mass Effect 2, Oblivion, or Fallout 3.

 

[gunningyoudown]

did it with heavy rain and uncharted 2

 

[neyrey64]

either WoW or Mass Effect 2

 

[atomictoast]

Fallout 3, any of the Disgaea Series, Garrys Mod 10, or Team Fortress 2 will do.

 

[skystryke]

Oblivion easy, plus I'll probably do that tomorrow anyway since I finally got my copy to work again.

 

[crudus]

Mass Effect 2. Mainly because I think I could beat it in that time.

 

[Nouw]

Starcraft 2. What? 1 match could last that long.

 

[Redlin5_v1legacy]

I could easily do 48 hours with Freelancer. I love that game from start to sandbox neverending finish. I would be spared... Hopefully.

 

[Pegghead]

Easily World of Warcraft.

Or if it couldn't be an online game probably something that's also enormous with elements of stat building and roleplaying.

 

[mkg]

Diablo.

 

[Dr. Paine]

Pretending the aliens could keep me awake/hydrated/fed...

Final Fantasy XII. Mostly level grinding. Or possibly the Prime trilogy... (hey, it all comes on one disk.)

 

[ecoho]

Starcraft 2. What? 1 match could last that long.

im with you id rather play that but if it had to be a console id chose crackdown 1 and just get all the agility orbs again that takes 72 hurs to do trust me i did it in one siting.....never again.

 

[KrazyShrink]

I'll get hate for this, but probably MW2. It has it's ups and downs, but I still love it. Or I could try WoW for the first time...

 

[Chancie]

Either Okami or Shadow Hearts: Covenant. I haven't played either one in a while and they both could last me 24 hours.

I'm leaning towards Covenant, though.

 

[zatzie zombie num666]

soul blade

 

[Vilcus]

If I was given the game, along with a rig powerful to play it, then I'd pick Starcraft 2.

If I have to choose a game I already own, then I pick the original Starcraft. Campain will take me roughly 8 hours. Afterwards I can just play skirmish games for the remaining time (once played online with 5 friends and we stayed up for 37 hours playing Skirmish games, as well as custom games).