7. Fiji
Who said a jaunt to the South Pacific had to cost an arm and a leg? Among Fiji's 300 isles, there's something for the budget traveler, too. A stay on the main isle in Nadi, for example, might cost you $188 a night for a mountain-view spa room at the Anchorage Beach Resort, including continental breakfast every day, plus free use of canoes, kayaks, and snorkeling gear. Or you could head to the Crow's Nest, an intimate resort of individual villas among bougainvillea vines, hibiscus blooms, and tall coconut palm trees, set against the Coral Coast. The nautical-themed villas are on terraces, each with a magnificent view of the lagoon and ocean, and rooms start at just $79 a night.

Divers might want to check into Fiji's fourth largest island, Kadavu, along the Astrolabe Reef, where rates at Mantana Beach Resort or Mai Dive—from $195 and $280, respectively—include the boat, dive master instruction, weights, tanks, and two dives a day. Or try Dolphin Bay Divers Retreat on Vanua Levu near the Garden Island of Taveuni, where you can explore the world-famous Rainbow Reef.

For the true bare-bones traveler—and environmentalist—there are a cluster of eco-resorts, sans bells and whistles, like Wayalailai Ecohaven Resort in the Yasawa Islands, where you'll pay only $60 per person per night. And among the Yasawas, you'll find plenty of inexpensive (sometimes, free) activities to tackle, such as snorkeling or trekking to Wobbling Rock, Gorilla Head Rock, ancient village sites, plantations, and the Three Sisters.