We stayed at Henderson Beach SP this April and had a great time. Wonderful campsites with lots of privacy from one site to another. Good beach access and yet there is all the convenience of malls and restaurants close by.
We also enjoyed the Yellowjacket Campground (Old Town, FL) on the Suwannee River close to Manatee Springs. Great place to kayak and then day-trip to Cedar Key for salt-water marsh paddling.