What are the criteria for inclusion on this site? In no particular order I have a couple that could be added:

Plymouth Municipal in Plymouth, NH. GA grass strip, I believe. Follow the signs towards Quincy Bog from 93. If you go through a covered bridge shortly after turning off 25, you're on the right road.

Blueberry Hill in Western MA. Private grass strip. Former(?) home of The Cookie Lady. PYO Blueberries. About 10 miles north of Upper Goose Pond cabin on the Appalachian Trail. Northbound hikers will appreciate it greatly if southbound hikers bring blueberries for the pancakes the next morning.

Post Mills, VT. Grass strip, has very active soaring and ballooning communities. Home to the Vermontasaurus and a great deal of other folk art-type stuff. Worth a trip if you're in our particular middle of nowhere already. No, I did not know Brian Boland. He died before we moved to the area.

Tonopah, NV is on there. I spent a night with my tent pitched in their hangar (with permission) in 2006 bike touring out west. That one remains active.

Post Mills is most definitely active and they release sailplane tows over our house regularly. Often you can find someone setting up for a baloon flight on a nice morning. I've driven by Plymouth Municipal a bunch going to and from Rumney for climbing when I lived in Boston, and there were a bunch of planes last time I did that. Haven't been by Blueberry Hill in a while, but sure was happy to gorge myself on blueberries on my way to Katahdin in 2010!