It is usually the Danes who are the happiest people in the world. In 2015, however, the Swiss were happiest. The Danes were not too happy about this, but apparently they did not get too sad because as of 2016, the Danes are again the happiest people in the world, the Norwegians are number 2, the Swiss are in 3rd place and no Nordic country falls outside the Top Ten:
You may find the full report and more info here: http://worldhappiness.report/ed/2016/
The question is, of course: Why are the people of the Nordic countries so happy all the time? And why is it always countries like Switzerland, Netherlands and Canada we compete with in these international surveys?