I'm a huge fan of the Grant Bar. It's wonderfully old school and authentic, visiting there is like stepping back 50 years in time. I highly recommend their pork chops. Their Coconut Cream Pie is a specialty that will be featured in the upcoming national Pie show by the very talented Rick Sebak of WQED. It is light as a feather, flavorful, and everything a great Coconut Cream Pie should be.
This place is authentic Pittsburgh, nothing fancy, but reasonably priced and a real slice of restaurant history. The bar part is in the front, but the dining rooms are in the back and the atmosphere is like hunting lodge.