Dr. Carl Sagan

...is alongside Mr. Rogers in one of the greatest gifts to humanity.

If we could all take this to heart, we'd live a lot richer.

https://getpocket.com/explore/item/the-baloney-detection-kit-carl-sagan-s-rules-for-bullshit-busting-and-critical-thinking

Definitely one the coolest dudes in our lifetime.  Even the story of how he proposed to his wife was badass.  

https://www.npr.org/2010/02/12/123534818/carl-sagan-and-ann-druyans-ultimate-mix-tape

I'm a big fan.  Also a big fan of Richard Feynman.