Pastor is king in Mexico City, and thus this list leans heavily towards the spitted pork. It's rare to see an authentic version in the States, but in Mexico City (or, as locals call it, D.F., which is short for distrito federal) most taquerias have a simmering cone of the red chile-marinated pork outside their doorstep to attract passersby. The cherry on top is a hunk of fresh pineapple.
Basically it's the Mexican version of doner kebab: the meat slowly rotates next to a flame, cooking the outer layer but keeping the interior at food-safe temperatures. The guy tasked with manning the spit will slice off hunks of pork directly into a tortilla, then take a skillful swipe at the pineapple to add a citrusy kick. It's not unusual to see the pastor dudes catch the pineapple behind their back. It's also not uncommon to see them fail miserably at this trick.