We just return from a wonderful five day/four night stay at Cherrystone Campground on the Chesapeake Bay. It's about an eight hour drive south on the NJ Turnpike and route 13 through DE, MD and into Virginia.
The campground was clean, well kept and the staff was very helpful and friendly. They have full hook-up (30A and 50A) as well as cabins you can rent if you don't have an RV.
For anyone that enjoys watersports, fishing, crabbing and beautiful coastal scenery Cherrystone is a place you should consider. It's also a short 40 minute drive over the Chesapeake Bay Bridge and Tunnel to Virginia Beach.