When most people in this town talk about great Mexican food, they're talking about the kind of burrito you find at El Ranchito. Don't bother telling them that the burrito was invented by Mexicans working in California, not Tijuana; and don't dare suggest that this style of burrito was designed to appeal to the lowest common denominator. In fact, since you can't beat them, you might as well join them in digging into an overstuffed, cheese-covered tortilla smothered with Denver's take on green chile. El Ranchito's burrito supreme is an exemplary version of this quasi-Mex mainstay, bursting with well-seasoned meats mixed with diced tomatoes, and topped by thick, heavy guacamole, lots of sour cream, a quilt of melted yellowish-orange cheese and a sweet, gravylike green.