Ipanema, Rio de Janeiro: Yes, this is one of the most urban beaches in the world, but it's still one of the country's prime tanning spots. The long stretch of white sand is perfect for observing the tan and lovely (male and female alike). Or watch a game of volleyball while having a beer and some fresh seafood; if you feel like it, go for a swim or a stroll.
Praia dos Castelhanos, Ilhabela: Ilhabela's prime unspoiled beach is long and wild and completely undeveloped; mountains covered in untouched Atlantic rainforest provide a stunning backdrop. Access is by boat or over a bumpy rutted track, but the views are more than worth it.
Boipeba, Bahia: The perfect island getaway, Boipeba makes Morro de São Paulo seem busy and hectic. Just south of Morro, Boipeba offers glorious empty beaches framed by rows and rows of palm trees. At Boca da Barra, where the river Inferno meets the ocean, huge sand banks appear at low tide. You can choose whether to swim on the freshwater side or play in salty ocean.
Porto de Galinhas, Pernambuco: Development in Porto de Galinhas has been kept resolutely small-scale. No high-rises mar the unpretentious town of Porto de Galinhas, which boasts perhaps four streets -- enough for a dozen restaurants, a bank, some surf shops, and a beachside bar or two.
Ponta Negra, Manaus: Not an ocean beach but a river beach, Ponta Negra, on the shores of Rio Negro, is the most popular tanning spot in the dry season. All the standard beach accouterments are present, including vendors plying food, drinks, and souvenirs. Beach kiosks serve up snacks until the wee hours.
Fernando do Noronha: The island archipelago of Fernando do Noronha has so many spectacular beaches, it's hard to single out just one. Praia do Leão offers wild crashing surf and sea turtle hatchings in season. The most gorgeously secluded is Praia da Baía do Sancho, a crescent of red sand on shimmering clear blue water that can only be reached by clambering down a rickety iron ladder through a chasm in the cliff side.
Praia Mole, Florianópolis: Praia Mole is one of the most popular beaches on the beautiful southern island of Santa Catarina (aka Florianópolis). Perfectly white fluffy sand, lush green vegetation, and rocky outcrops give the beach an isolated, paradisiacal feel. Yet, the strand is anything but quiet, packed with a bohemian crowd of locals from Floripa, yuppie tourists, surfers, gay and gay-friendly sunbathers, and families.