Corner Bistro [331 West 4th Street, New York; Menu]
Strong competition for the burger joint (and maybe my personal favorite), this downtown landmark is cheap, delicious, and open late. You may have to wait for a table in the back (at any time of day or night), but you can drink cheap beers (my favorite is McSorley's Dark) while you do so. Don't mess around with something like chicken or chili. Get a cheeseburger and fries. Your taste buds will thank you.