One of the hazards of the late-night-life is that often, the food energy from dinner is burned up long before it's time to head home. I used to whine jealously about other cities like NYC and the abundant availability of food past midnight. However in the last few years, I've watched the options grow, and my stomach has been very, very happy.
Opal on 9th and Lincoln has a long running late night sushi happy hour from 10:30 pm-1 am, every night!
For the sweet tooth craving after a Bluebird Theatre show or too much tequila at Mezcal The Shoppe on Colfax is open Fridays and Saturdays until 2am offering cupcakes, ceral and other sugary goodness!
Two Fisted Mario's on Market and 16th, has been a longtime late night pizza location- staying open until 2 am on weeknights and 3 am weekends!
Then there's the amazing Leela European Cafe on 15th between Champa and Stout- open 24 hours!
I heard on NPR about the site yumtacos.com which lists taco trucks! So far there's none listed on the Denver portion of the map, but hopefull that'll change soon! Mmmmm.