Caladesi Island State Park Beach was voted the best beach in the USA in 2008 (it came 2nd in 06 and 07). This beach is located close to the city of Dunedin in Florida, some 36kms west of Tampa. In addition to its fantastic stretches of white sand there are a number of other activities you can avail of. These include a nature trail, a marina, the picnic pavilions and the bathhouses. You can also go fishing, shelling, kayaking, boating and hiking.
Hanalei Bay came 2nd in 2008 and you'll find it near the town of Hanalei on the northern coast of the island of Kauai in the state of Hawaii. Here you can enjoy the most pristine Blue Ocean and over 3kms of beautiful sandy beach. It's a popular area for sailing snorkeling and swimming. To one side of the bay there's the Princeville Makai Golf Course which offers spectacular views over the bay and the pacific.
Back in Florida you'll find Siesta Beach close to Sarasota. This beach is found on Siesta Key which, along with Lido Key, is world famous for its fine beaches. The sand here is 99% pure crystal quartz which makes it one of the cleanest whitest sands in the world. The beach is equipped with volleyball courts and a cook out area where you can cook your own BBQ (though you'll have to bring your own charcoal).
Situated on the east coast you'll find Coopers Beach in the state of New York. It's on Long Island near the town of Southampton and a mere 145 kms from New York, perfect for a day trip out of the city. Though not known for year round good weather, when the sun shines, Coopers Beach rivals the best in this list. After enjoying the beach you could go for a look around the town of Southampton which was the first European settlement in the state.
Many of these beaches are a little out of the way from their home town or city so you will probably require a car to get to the beach. Just don't forget a packed lunch and appropriate sunscreen.