Guernsey: 80.42 Years
The island of Guernsey, located in the English Channel, is a British Crown dependency, but it's not part of the U.K. The reason for its high life expectancy is simple: It's extremely wealthy. Very low taxes make Guernsey a popular destination for tax exiles who can afford the very best in nutrition and medical care. More than half of the island's income comes from financial services -- which means well-paid desk jobs -- with very few people working in heavy industry.