Consider buying a CityPass, a group of tickets to six top-notch attractions in New York: the Empire State Building, the Guggenheim Museum, the American Museum of Natural History, the Museum of Modern Art, the Metropolitan Museum of Art (including the Cloisters), and Circle Line Cruises or admission to Liberty and Ellis Island. The $74 pass, which saves you half the cost of each individual ticket, is good for nine days from first use.
Discount coupons are available at the city's official tourism marketing bureau, NYC & Company (www.nycvisit.com), near Times Square.