This likely is the best Mexican food in Madison. Super authentic, great prices and friendly staff. Try the pambazo sandwich, it is spicy and overall ridiculously good. It is a large sandwich filled with chorizo and potato and dipped in a spicy guajillo pepper sauce. I recommend their chorizo if you enjoy spicy food! If spice is not your thing their carnitas is excellent and flavorful. Their guacamole is quite nice as well! Give this hole in the wall a chance if you love excellent, authentic Mexican food.