I first tried Earl back earlier in the year on my friend's bachelor party. After a long night of "bachelor party-ing it" around the strip, we hit Earl for some late night food. Let me tell you...what a gem. With that group, we made it our go-to place for inexpensive food (sandwiches are $7-ish) on the strip, stopping in 3-4 times. I had several of the sandwiches, and all were as good or better than most other sandwich shops out there.
On my last trip to the strip, we stopped in again, and made fun of ourselves for it. It's always busy, no matter what time you go, literally. I guess that says something, with quality and price in Vegas. Check it out, whether looking for an inexpensive meal or for that late night visit after an all-night bar/hotel hopping extravaganza-in-need-of-something-edible-and-cheap-before-you-crash-out.