Denver drinkers used to be content ordering snifters full of ice, cheap tequila, sweet-and-sour mix that made your teeth squeak, maybe a lime wedge, and all sorts of top-secret (and cheap) ingredients guaranteed to give them a big headache in the morning. If they wanted to get really fancy, they might even order their margaritas frozen so they didn't have to taste what was going to give them a big headache in the morning. But then Denver drinkers started studying tequila, differentiating the regional nuances, demanding fresh lime juice and margs served coin-style. While local bars increasingly focus on specialty drinks that quench the ever-growing thirst for better margaritas, they often give scant attention to the house marg. But that's not the case at Mezcal and its sibling, Tambien, which continue to turn out spritely, fresh-tasting, potent house margs that feature plenty of quality tequila, plenty of fresh juice, and just a spritz of carbonation to keep your evening bubbling along.