Bloomberg Billionaires [bloomberg.com], designed by the Bloomberg Visual Data team, is a daily-updated interactive dashboard of the world's richest people.
Many filtering and graphing features are relatively hidden behind beautiful buttons, such as a number-only view in the ranking list, and the variable choice of the vertical and horizontal axes in the scatter plot view. Also, a dynamic timeline at the bottom allows one to explore the historical rankings of the last 10 months.
Accordingly, one can perceive how the large majority of billionaires has significantly been gaining wealth during the last year (and daily gains or losses of more than 500 million dollars in not uncommon), while very few have seen any relative losses. For those wanting to marry a billionaire without any direct heirs, the number of children can be plotted as well.