The US Census Download Center contains rich information on its countries demographic data. Here you can find a piece of R code that uses the highcharter package in R to create an interactive map showing the median household per country.
The Washinton Post is known for the lovely visualizations accompanying their stories. In a recent post, they visualized how long it would take you to get out of the downtown areas of various cities. They compared all the major U.S. cities and examined different leaving times. Unfortunately, I cannot copy the visualizations’ text here, but please do have a look at the originals.