Whispering Pines Campsites & RV Park at 550 Sandhill Road, Greenfield Center, New York.

Beautiful campground, we were there over a Dave Matthews concert weekend (didn't go to the actual show) but the place with packed with concert goers and it was a very quiet night. Spacious sites with full hook-ups and well treed to give you a bit of privacy. Prices were decent as well. Just fair warning, apparently there is a charge for using their showers $0.50 or so for 4 minutes...a couple people I was travelling with tried to use it and informed me of this so I thought I would pass it along. I had my RV and enjoy showering in it, so it really didn't concern me at all.
I will happily return next time I am in the area.