I can fall asleep in almost any circumstance, if im tired. Im listing only a few of the "funner" ones.
Fell asleep in a HMMWV a few times, While driving (Quick doze off, no more than a few seconds), Marching (Seriously), Laying on the ground with my helmet resting on my M4(in basic) while it was raining, Laying in the snow for about an hour (Yesterday), I learned to fall asleep while standing up when i was on gate guard duty, I would be standing in the middle of the road(I could do that for minutes at a time).
My favorite place to sleep when im not in bed is on the toilet, Stayed hidden and got out of so much work by doing that. Also during the winter our bathroom is the warmest place in the house because of the water pipes and the snakes.