Stunning visualization of world health data
One of the most beautiful interactive charts I have ever seen is Gapminder World 2006, which merges impressive data visualization technology with human development statistics.
This chart allows you to compare worldwide statistics such as population, % of women in the workforce, and poverty. The two axes can be changed on the fly, and on mouseover each country or geographic region is highlighted. There is even a timeline with a playback feature that shows an animated progression of the chosen statistic over time, such as a depiction of the falling birth rate from 1960 to 2000, or the rise in Internet usage. The chart can even be superimposed on a world map for a different perspective.
The Gapminder.org website also offers printable versions of world statistical charts such as education, life expectancy, and HIV prevalence.