hmmm I wouldn't consider Ellsworth a beach town? The coast of Maine becomes predominately rugged and rocky after you get further down east from Casco Bay (Portland).
For Maine - Old Orchard Beach, Kennebunkport, Ogunquit, Wells and York are what I would consider beach towns. There are other smaller beach "communities", but those aren't towns in my opinion - Biddeford Pool for example.
New Hampshire - Hampton Beach, Seabrook. There are town beaches in places like Rye and N. Hampton, but no services at the beach, such as restaurants, bars etc...
Massachusetts- Newburyport, Ipswich, Rockport, Glochester..........to Cape Cod - every town on the Cape. All of Nantucket & Martha's Vineyard.
Rhode Island -Narragansett, all towns along Block Island Sound from South Kingston to Westerly.
NY - all of the coastal communities on Long Island
New Jersey - the infamous Jersey Shore all seaside towns from Long Beach to Cape May.