When you're tired and just had a fun day of partying, Secret Pizza is always there for you 24/7. The pizza in itself is solid (chicken pesto is my fav) and for $5 on the strip, at the fancy Cosmo Casino, next to Marquee, it's a good deal. The line moves fast and it does the job to sober you up / get you a pick me up for the next activity.
Go to the 3rd floor up top at the Cosmo.