Winner: South Water Caye, Belize
There are hundreds of beautiful cayes along Belize’s Caribbean coast. Our pick is South Water Caye, east of Dangriga—a 15-acre island inside the country’s largest marine reserve. You can paddle the shoreline, snorkel at night, and, if you’re lucky, dive with whale sharks off a nearby atoll. The Pelican Beach Resort is one of just three on the island and has eight sandy cottages, four kayaks, and a sister property on the mainland—which makes transfers easy (from $369; pelicanbeachbelize.com).
Runner-Up: Tikehau Atoll, Tahiti
Sometimes called the Pink Sand Island because of the color of its shores, Tikehau isn’t a beach so much as a ring of them—a Tahitian atoll in the Tuamotu Islands with a 180-square-mile lagoon twinkling in the middle. The choicest views are from the 24-suite, 13-bungalow Pearl Beach Resort on the southern end of the atoll (from $626 per night; spmhotels.com/resort/tikehau). Fly directly from Tahiti’s Fa’a’a airport, then rent an overwater bungalow with a glass floor panel and watch angelfish swim past.