Smoke is easily the best casual restaurant in the Pittsburgh area.
Let's get a few things out of the way. This isn't a Mexican taco place. The flour tortilla is only a vehicle to get the array of smoked meats into your mouth. So you SoCal kids looking for a delicate corn tortilla can quit now. Smoke is its own genre.
Yes it is small and sometimes slow. Suck it up, good things come to those who wait. They don't take reservations but here is a tip. Go put your name in and then walk around corner to Blue Dust and have a drink. Smoke will call your cell when a table is ready. Bring cash and your own booze. They have fresh margarita mixers so half a bottle of tequila is a good addition. If booze isn't your style, try the horchata.
My favorite is the rib taco. I liken it to a McRib sandwich with great ingredients. The brisket, chicken apple, veggie and BLT are all standouts. One of the best things on the menu is the breakfast taco. Served all day, it is great anytime and you can add a meat of your choice to it.
One of the secrets of smoke is the wings. They are only available on Thursdays and they run out, but man oh man are they amazing. Smoked then fried, these are spicy and awesome.
If you are really lucky you will be there on a day that someone has baked. The chocolate brownie with peanut butter marscapone frosting are amazeballs!