I remember a couple of local ones:
First, in downtown Allentown there was a major department store at Ninth and Hamilton Streets. Hess Brothers, and later Hess's had a fantastic restaurant in the basement of the flagship store which featured live fashion shows with models walking between the tables, and kid's meals delivered in toy oven and served to the table from the oven. One of the specialty items was strawberry pie which was more than a meal itself. Kid's were able to get the clown sundae with an ice cream cone hat. I remember standing in line a number of times and even as a kid, 30 minutes was not too long to wait for the special meal.
Another favorite in the Lehigh Valley was Shankweilers at the intersection of Old US 22 and PA 100. It was a stately old home with a country look and specialized in the PA Dutch feature of Chicken and Waffles. It now is a branch of a local bank. What a loss. My favorite hobby shop used to be next door, but Don Mohr's Hobbyland is long gone as well.
I ate many a meal Howard Johnson's, especially on the PA Turnpike when all the quaint stone rest areas featured HoJo's and my favorite french fried clams.
And my favorite as a child when going to any big city was the Automat where I could put my coins in a slot and open the glass door for my sandwich and desert. What a great way to eat when on a school bus trip.
There were many more favorite local diners, but they were all similar. The most memorable was when the old Thomas' Diner on Tilghman Street (old 22) in Allentown became the Blue Moon Diner, and had a 57 Chevy mounted on the roof. They brought back the diner specialties of meat loaf, mac and cheese, BLT, real mashed potatoes and real milk shakes. I still miss that one a lot.