Years :
Fertility Rate Vs Life Expectancy
Bubbles!!! How captivating they are? Made with soap or DATA they hold everyone's attention. In 2014 I was captivated by Rosling's talk about changing the Mindset with the Dataset. Not for the content but for the visuals. Underlying the visuals, I knew that data was there. How the data gets there? That is a different story.
With D3, it is trivial to make bubble charts. It is not trivial to get the Data to D3. After trying other libraries that were filled with layers of abstraction, libraries that were simple in certain environments, I realised the power is with who go below these abstraction, and learn to solve the problems on their own. Even if it means learning new language like JS and D3.js to visualise the data.