+1 on Cape May. Cab to an historic shore town with some very good restaurants. Aviation museum on the airport, too.
26N (Ocean City) has a nice cafe on the field, but IMO the more interesting attraction is the short walk to the boardwalk along the ocean shore
12N, Aeroflex Andover is on the edge of Kittatiny State Forest Park. Picnic areas with barbecue grills, hiking trails, and a small lake (no boat rentals, though).
39N, Princeton. A cab to downtown Princeton. Walk the striking University Campus and town. Excellent restaurants, as well.
N40, Sky Manor has an on-field restaurant that is a cut above the standard airport cafe and a pleasant setting. Lots of plane traffic on weekends and picnic tables provide good views of the runway. Restaurant attracts lots of drive-in traffic as well as fly-in.
N07, Lincoln Park is another airport with an on-field restaurant that is good enough to do most of its business via drive-ins. Patio provides good runway view. Not so much from inside seating.