For those of us Philadelphians that don't want to travel too far to get back to nature, French Creek State Park is a great choice. It's only 1.5 hours tops from downtown Philly but it's far enough away to get that ""leaving it all behind"" feeling. French Creek is one of the cleanest State Park camping facilities I have ever been to, and the scenery is fantastic. Great hiking, frisbee golf, local wineries, and historical sites nearby.
Pros: Clean, electric campsites, pretty fall foliage