The happiest country of world is Finland. Finland became the happiest country second time.

These are the top happiest countries in the list of 156 countries.
1-Finland
2-Denmark
3-Norway
4-Iceland
5-Netherlands
6-Switzerland
7-Sweden
8-New Zealand

India got 140th place
Britain  15th
America 19th
Pakistan 67th

The most unhappy country is South  Sudan.

South Sudan
African Republic
Afghanistan
Tanzania
Rwanda
Yemen
Malavi
Syria

Bhutan proposed this happiness proposal in 2011 UNO,since than

20 March​ is observed Happiness Day

The first list of happiest countries was published in 2012 and Bhutan got the first position.

This is based on given standards

Per person GDP of the country
Social Cooperation
And Courrption
Social Independence
Questions based on healthy life.