Here are some of my favorite data visualizations that I've learned to make throughout my coding life. The code to reproduce each of my visualizations is included as a link for each one.
The Number of Miles Traveled Has the Greatest Impact on the Price of a Plane Ticket, followed by the Airline Company you Fly Wtih
A Stacked Histogram Bar Chart Shows the Spread of Bleached Coral Reef Sites from 1998-2010
The Optimal K-Means Value Lies within the Elbow, so at either 3 or 4 for this Particular Dataset