Ate at the Earl of Sandwich a few times during our visit. Reasonably priced and tasty, this sandwich shop inside of the Planet Hollywood hotel is busy at all hours of the day (it's open 24 hours).
All of their sandwiches are hot and use high quality ingredients. Of the ones I tried, the Earl's club was by far the best (I found the Chipotle Chicken Avocado a bit soggy, and the sweetness of the cranberries in the American BLT a bit distracting).
Aside from their hot sandwiches, they also offer salad, soup, wraps, dessert and breakfast sandwiches. Would definitely return the next time I'm back in Vegas.