I tend to agree with Paul Graham's blog post [1] about how easy it is for entertaining talks to have little substance at all. For example, I showed this TED talk [2] in a lecture to illustrate the power of posture, voice and body language in crafting a talk devoid of real content. The talk manages to be extremely entertaining. However, I'm secretly afraid that talks like [2] are entertaining not despite a lack of content, but because of it.
I think that really good public speakers manage to be easy to listen to despite delivering real, hard content. Digesting facts and understanding arguments is hard work, and a good public speaker should make it easy for the audience to really learn something new.
That's why my favourite speaker during undergrad was the late Hans Rosling, who had a knack for telling the stories behind that data in an entertaining way. Rosling's talks were often about the public's misconceptions about the world, about how our view of the world was outdated. He began his talks with humorous anecdotes, then delivered his message by taking his audience close to the data with a contagious enthusiasm. The choice of data visualization was most important, and can be anything from an animation showing changing income distributions [3] to stacked toilet paper rolls showing population growth [4].
A great computer science speaker is Gary Bernhardt from Destroy All Software [5]. If you are old enough, you will probably remember his "Wat" talk [6], and his less hilarious but more insightful talk on software Boundaries [7]. In his talks, Bernhardt introduces concepts in a meaningful order, and explains even complex concepts in a clear and concise manner.
I can't finish this blog post without mentioning Bret Victor [8] and Andrew Ng [9], both experts in their chosen fields. Their fields and their styles could not be any more different. But both of them tend to choose other mediums to communicate their ideas, and both their talks tend to be less entertaining than they are mindblowing. Both these people find ways to distill their ideas down to their essence, then explains them in simple words. Even though they may not make as many jokes as Berhardt, Rosling, or the talks Paul Graham refers to in his blog post, Victor and Ng's talks are worth watching.
This blog post was written so that I could follow my own prompt at https://www.cs.toronto.edu/~lczhang/290/blog.html#b5
References:
[1] http://www.paulgraham.com/speak.html
[2] https://www.youtube.com/watch?v=8S0FDjFBj8o
[3] https://www.youtube.com/watch?v=hVimVzgtD6w
[4] https://youtu.be/um5vdYcMmCE?t=1346
[5] https://www.destroyallsoftware.com
[6] https://www.destroyallsoftware.com/talks/wat
[7] https://www.destroyallsoftware.com/talks/boundaries
[8] http://worrydream.com
[9] https://www.youtube.com/results?search_query=andrew+ng+talks