According to the study's methodology, the happiest countries on Earth are, in descending order, Denmark, Switzerland, Austria, Iceland and The Bahamas. (I would have thought that Nordic countries such as Iceland would have been penalised by the long winter nights and incidence of Seasonal Affective Disorder; perhaps the spectacular landscapes and general coolness makes up for that.) The USA is 23rd ("We're #23!"), and the UK is #41; meanwhile, various Japanophiles will be disappointed to find that Japan scrapes in at #90, being slightly sadder than the median. The least happy places surveyed are Zimbabwe and Burundi.
Looking at the map, which is shaded according to colour, certain patterns emerge. Scandinavia and Finland are the same sanguine shade of red as Iceland and the US; Ireland is happier than the UK, and France and Portugal are the least happy countries in western Europe. Meanwhile, Australia and New Zealand are both in the top shade of happiness, as is Bhutan; Africa is generally a deeply unhappy place and Russia is quite gloomy. Not surprisingly, no data exists for Iraq, Afghanistan, Liberia, Somalia or North Korea, though one can guess that they're probably not brimming with joy.