https://www.nytimes.com/interactive/2019/12/02/climate/air-pollution-compare-ar-ul.html
So this is a very advanced data visualization, and it's so good! It allows you to compare air quality in your city to other cities, including the most polluted ones. There is a scale at the top of the page that shows how much particulate pollution is in the air you breathe, and in the background a graphic of floating dots representing particles. As you scroll down to cities with worse air quality the floating dots increase so it gives the reader a better understanding of the density of these particles that are in the air.
The dataset is good because there is high contrast. For example, I compared Seattle (where I live and where there is growing concern about air pollution) to New Dehli, a place with some of the worst air pollution in the world, so the contrast is very obvious.
I think they could have added some additional chart types as well like a simple bar graph to compare cities.
In this visualization I think the interactivity really adds value because you can select your city, think about the air on its worst air quality day, and then imagine what it must be like in some of the worst polluted cities, most of which are in Asia.