In Texas, the norm is Brisket, Chopped Brisket (sandwich), Chicken, ribs (beef and/or pork), sausage. Other meats that show up are pork loin, pork chop, turkey, and mutton. Generally meats are available as a plate, sandwich or lb. Cabrito, barbacoa, and al pastor shows up at taco shacks. General sides are bread (included), slaw, onions (included), jalapenos, and potato salad.
Now one shop I like does add a bit. They have bowls - 1/4lb brisket and 1/4lb sausage over beans and 1/4lb of chop over fritos and beens, or the T-man (all of the above). They also serve bake potatoes stuffed with brisket or chop. Another place used to sell chicken breast by the pound (which made a darn nice sandwich cheep).