When I worked at Downtown Disney World last year, Earl of Sandwich was my lunch of choice. Every day. Now that I'm back on the west coast, our nearest Earl is in Vegas so of course when I went there for my birthday I stopped on by!
The line is usually insanely long if you come around noon but it moves really really fast. I usually order the Hawaiian BBQ and Cannonballs, both are delicious. Cannonballs is the kind of sandwich you can just bring around with you and it'll still be delicious cold! Also, I have a weakness for their original chips. OMG! How I've missed it!
Earl of Sandwich is a great place to grab a bite and it's significantly cheaper than most places on the strip not to mention probably better for your health-wise. The only down fall is that the location is sort of small, but they offer more tables over towards the mall side.
Another plus? This place is open 24 hours a day! :D