For a quick meal, there's Canters at Treasure Island. I didn't think it was as good as Canters in LA, but I only ever ate at Canters in LA when it was really late, I'd just come from a concert, and was in a generallly good mood, so that might have colored my experience. Anyway, the one in Las Vegas has top-notch deli sandwiches, the big, piled high with meat and little tiny slices of bread kind.
I can't say enough good things about Lotus. I see that the original poster is already going there, so it's not like my reccomendation will sway anybody, but they deserve all the praise they get and then a little more. So good, so friendly, so incredibly willing to take you on a culinary adventure if that's what you want, and to do their best to make even the boring stuff good.
Another casino choice is Noodle Asia, inside the Venetian. Surprisingly good quality pan-Asian noodle shop. It's pretty odd to find cheap, good food like this in Vegas.
For a list of restaurants, sorted by quality, under $15 and on the Strip (only in Casinos),
my Vegas web site. I don't get any money or anything if you click here. These are just some of the places I (and my friend who does the site with me) find good.