American travellers have voted Sydney the world's best city for the eighth time.

The 2000 Olympic city nudged out Bangkok, Rome, Florence and Chiang Mai to take out the US Travel and Leisure magazine's top spot, with the publication's home city New York coming in at sixth.

Sydney was not Australia's only shining light in the awards, with the Great Barrier Reef islands rating No 5 in the world's top polling islands and No 1 in the Australia, New Zealand and South Pacific section of the same category.

"Which country has the world's friendliest natives, an exhilarating wine scene, world-famous beaches and stunning natural wonders? Australia, of course," a spokesman for the magazine said.

"Year after year, Sydney tops our readers' World's Best Cities list and year after year, travellers return from the other side of the world exhilarated with what they've seen."

Tourism Australia boss Scott Morrison said his organisation's toughest challenge was to convert that love of Sydney into visits.

"And that's our focus at Tourism Australia," he said.

A Tourism Australia spokesman said Australia was often voted one of the most desired destinations in international surveys.

"People have a high preference to visit here, they value the Australian people and the lifestyle we've created," he said.

"What we want to do is get people out and about and move them beyond the gateways."

Sydney often came up trumps because of its easily recognisable landmarks like the Harbour Bridge, the Opera House and the harbour, the spokesman said.

The magazine's 900,000 subscribers were asked to evaluate each city by its sights, culture, arts, restaurants, and food, people, shopping and value.

This year Sydneysiders rated particularly highly in the "people" category.