Among New England states, Rhode Island, the Ocean State, has a reputation for great beaches, but in fact all of the New England states except Vermont have good ocean beaches. (Vermont has lake beaches.)
Rhode Island's beaches are either facing Long Island Sound or on Narragansett Bay, which also provides some protection.
Among the favorites are Charlestown's East Beach, Newport's Easton's Beach, and Narragansett Town Beach in Narragansett.
Massachusetts has all those Cape Cod beaches (including Cape Cod National Seashore), as well as others on the South Shore near Plymouth, the North Shore and Cape Ann, and the islands of Nantucket and Martha's Vineyard.
New Hampshire has long, fine Hampton Beach, as well as the beaches on its lakes, particularly huge Lake Winnipesaukee.