Ireland was followed by Switzerland, Norway and Luxembourg. All but one of the top 10 were European countries.

The USA languished in 13th, while Britain was 29th - the lowest of the pre-expansion EU nations.

The survey was prepared for the Economist's "World in 2005" publication, with the remit: "Where will be the best place to live in 2005?"

Researchers took into account not just income, but other factors considered important to people's satisfaction and well-being.

They included health, freedom, unemployment, family life, climate, political stability and security, gender equality and family and community life.

The Economist said: "Ireland wins because it successfully combines the most desirable elements of the new, such as low unemployment and political liberties, with the preservation of certain cosy elements of the old, such as stable family and community life."

The magazine admits that measuring quality of life is not a straightforward thing to do, and that its findings will have their critics - "except, of course, in Ireland".

The Republic has made significant gains from its membership of the EU, earning the soubriquet Celtic Tiger for its economic progress.

Commentators say it is widely admired by the EU's newest members, and has become a model for what they hope to achieve.

Although European nations generally do well in the survey, the continent's major industrial powers of France, Germany and Britain finish 25th, 26th and 29th respectively.

The researchers said although the UK achieved high income per head, it had high levels of social and family breakdown.

The worst of the 111 countries to live in was considered to be Zimbabwe, "where things have gone from bad to worse under [President] Robert Mugabe".