I graduated from Pitt in 1994, and I go back one of the first places I hit is Primanti Brothers. I usually hit the one write off of Pitt's campus, but there a few others spread around Pittsburgh.
The basic premise is the same for all of the sandwiches. You get the meat, and then they throw some coleslaw and fries on top. My usual is the egg and cheese, but they have everything from sardines to steak. I'm not sure about the other locations, but this ones sells beer. As a matter of fact, on the menu the steak and cheese is listed as the #2 best seller. The #1 best seller is beer!