Delaware House Travel Plaza on I-95 between exits 1 and 3. I've actually U-turned here once, as I'd only gotten on I-95 to go to the travel plaza and pick up a state map (it's one of the few places that have official DelDOT maps), then turned back.
Several service and rest areas on the Garden State Parkway in NJ:
Ocean View Service Area (MP 18.3);
Shoemaker Holly Rest Area (about MP 22);
Atlantic Plaza Service Area (MP 41.4);
Forked River Service Area (MP 76.0);
Monmouth Service Area (MP 100.0);
Cheesequake Service Area (MP 124.0);
Montvale Service Area (MP 171.0).