SoundBounder has done his homework as usual.
Sea Cliff YC is a good place to go to. If their kitchen is closed it is about a 300' foot vertical climb up into town to KC Gallagher's which has some nice seafood and burgers in a pub atmosphere: KC Gallaghers, Sea Cliff, NY : Reviews and maps - Yahoo! Local
The fun begins when you begin the descent back down to the water after a nice meal. People who belong to reciprocating clubs can get moorings for the night. There are a few other places to eat in Sea Cliff including: Tupelo Honey Restaurant Sea Cliff,NY
and a pizza place but I kind of like the laid back pub atmosphere of KC Gallghers's. Plus you get some exercise.
The other places right on the water in SC where in Mosquito Creek (actually Glen Cove) and seem to be closed at the moment. There were the 'Hideaway' and 'Steamboat Landing' which seem not to be able to stay open.
I would also recommend the Oyster Bay area for dock and dine opportunities (which would include a walk). Oyster Bay village has tried to make their waterfront more accessible for mariners and there are restaurants nearby.
One area that seems was missed was Huntington Harbor. There is a public park and dock on the eastern shore of this tightly packed and well protected harbor that is right across the street from an Italian restaurant called: Tutto Pazzo - Tuscan Italian Restaurant - Huntington, Suffolk County, Long Island, New York, Christenings
My sister's neighbor assures me that he took his big power boat in there, tied up for free and ate dinner and left while steering with one eye to get back out into Huntington Bay on his way home. I would ASSUME that a sailboat could make it in here and tie up but the tides would be worth watching. The Italian food is quite good and there are transient moorings available from a few clubs in this safe harbor. There are many other good restaurants in Huntington but most are just not right by the water front.
Six years ago we stopped in Mattituck inlet and tied up for free at the town dock at the head of the creek. The restaurant we found was not far from the dock but this would not qualify as the 'western LI Sound'.
DavidPM would know much more about the dock & dine opportunities on the CT side.
Louie's in Port Washington has not been great for a while. What is great is that they have a dock.