The world’s biggest and most important cities aren’t often the best places in which to live. High levels of crime, traffic congestion, and long commutes can worsen the quality of life. So which are the best cities to live in the world? We've put together a list of the world's 15 best cities, according to human resources consulting firm Mercer's 2011 quality of living survey. The annual report looks at living conditions in 221 cities worldwide and ranks them against New York as a base city in 10 categories such as economy, socio-cultural environment, politics, education, and the health sector. This year the survey ... (full story)