Did you know you can visit Mexico right smack in the heart of Vegas? Better brush up on that Spanish, else you might be in for quite a bit of "I want that" pointing to the workers who barely speak a lick of English.
Most people come here for the spicy adobada, but my favorite is the lengua tacos--the fattest, juiciest lengua tacos ever. You can also request grilled jalapenos and green onions at no charge.
The set up is a bit confusing if you've never been. There's a separate line for each type of meat. The lengua/cabeza is all the way to the right, the adobada is the long line you see, and the asada is to the left. You order, then bring your order to the cashiers to pay.
Open until the wee hours because you know you're going to need drunk food in Vegas.