We love the area of Pennsylvania up north and west of Scranton, near Adams State Park, and the area east of Wilkes Barre, around Tobyhanna State Park.
When we lived in NJ, we used to drive over and camp in the parks owned by Penn. Power and Light. They were great because you had electricity and water at each site, and they had nice food lockers up off the ground. There was one just South and West of Harrisburg, on a tidewater of the Susquehanna River that was gorgeous, with a stream that rushed down from the mountains and created a neat waterfall.
We're currently in love with Tioga and Potter counties in PA. The leaves are starting to turn. *sigh* just gorgeous.