This is from the OECD’s “Better-Life” index, which goes beyond the traditional (and often limited) variable of GDP and instead factors in 24 other metrics, such as life satisfaction (as measured by surveys), availability of housing, quality of education and infrastructure, etc.
Notice the gap between the richest and poorest within each country as well (especially in the US). Needless to say, some of these findings may be disputed or controversial. Click the hyperlink to see a more detailed report for each country, as well as those nations left out in the chart.
Source: The Economist