Bar none, the best late night snack I ever had was Yaki Soba at 4:30 in the morning in Yakosuka Japan.
My kid calls it Japanese Spaghetti
Chili Dawg with cheese and onions is a fave late night snack, but chili dawgs bark at night...
http://www.youtube.com/watch?v=V8b-ThHOi-4