Do you love history and have a little time free? New Castle is not far from Wilmington (though nothing in Delaware is far from anything else in Delaware). It's kind of like what Williamsburg would have been like if it hadn't been turned into a history park -- established in 1651, it's all narrow red brick, Founding Fathers slept or ate or stayed in virtually every building, landing site for even earlier historic figures (including William Penn), and there's a decent little restaurant about a block from shore -- Jessup's Tavern -- a historic tavern that offers "colonial comfort food." I ate at Jessup's, and it's not brilliant food, but it's good, and it's fun to be eating in historic surroundings. Considered a notch up (but I didn't experience it) is The Arsenal, which is connected to Jessup's. The Arsenal is historic, though "continental-influenced."
The New Castle visitors bureau offers the following directions: From Wilmington: Take King St. south, toward the train station, and follow the signs to Rt. 13 South. From Rt. 13, watch for the exit for Rt. 141 to New Castle; it will be on your right.
Jessop's Tavern
302-322-6111
114 Delaware Street
(reservations recommended -- only 12 tables, plus the bar)
The Arsenal at Old New Castle
302-323-1812
30 Market Street
(also recommend reservations)
These are the restaurants that serve historic food. If you'd like to just visit the town and then eat modern food, there several more options. For those options, plus more info on New Castle:
http://www.thebrandywine.com/go/histori ... astle.html