Cherry Hill just outside of Wash DC in Maryland, near College Park, is one of the finest ikn the country. Not cheap though, but worth every penny.
Rocky Gap State Park, in Western Maryland, is a very reasonably priced CG and in a gorgeous natural setting. Reservations are in order there, using the MD state park reservation service on the web. Ask for the "Ash" loop if you have pets and need power. All the other sites have water only. Dump site on the way out of the park.
Hello I can tell you about three cg that are top notch in pa. I live in Western part of pa. and only camped at a few cg but the three I will tell you are top notch.
1. Gas light camp ground. just off route 80 I think it's the old exit 12
2. rv camp village resort in mercer pa. off 80
3 . Big Bear campground. prospect pa just off 79.
4. I know I said 3 but this one should be on the list. Coopers lake. just off route 422.
If I knew what you liked to do and well be in this area I could help a little more.
P.S. two state parks to look at Cooks Forest and Clear Creek . Both parks are very nice
Good luck and have fun Jiggs
A real nice place to camp is around the Raystown Lake Area...Central PA. Since we have been out of the area for awhile I am not sure of the names. I do recall "7 Points" as being a very nice area on the lake. You can Google Raystown Lake and 7 points and see what you get. There atre a lot of activities on the lake and at 7 Points all summer long. I believe there are some State Parks in that area also that are very reasonable.