Both of these talks are in my top 5.

Edit (okay, here are the other 3):

* All the Little Things by Sandi Metz https://www.youtube.com/watch?v=8bZh5LMaSmE

* Programming is terrible—Lessons learned from a life wasted. https://www.youtube.com/watch?v=csyL9EC0S0c

* Some talk I saw by Dan McKinley on making Data-Driven decisions. I can't find the original video, but here's a really similar one: https://www.youtube.com/watch?v=SZOeV-S-2co