....I agree, 24 hours fail. If you can play 24 hrs, then you don't have stuff to worry about like school, work, whatever. No worries in the world = massive amount of MMO gaming deaths.
Give me no worries, bathroom, food, and entertainment that doesn't get boring, and 24 hrs is easy. At an overnight field trip, 3 other friends were with me in our room and since the teachers can't FORCE us to sleep....
We just had to have the lights off, and make no noise to disturb the others. Bit boring, but entertaining enough to just talk about random crap and do small screwing around. At god knows what time, (4, 5???) PM, 2 of them fell asleep, another was with me, but he didn't talk much. Got boring, no reason to stay awake, and slept.
Now, 3+ days THEN collapse...that's pretty impressive.