One thing that I was reminded by Heidi Hayes Jacobs was Gapminder. Gapminder is a data visualization tool that shows population, average lifespan, and average income over time. (You can also switch out the variables with things like "education," "environment," and "work.")
This is a fantastic tool to use with students to push critical thinking. How are variables related? How do they change over time?
Check it out. You won't be disappointed!