Neil deGrasse Tyson - Spark Arena, 9th July 2017
The good: Interesting tangents about everything from McDonald's, to mining gold on asteroids, to the timeless existence of photons, to the simulated universe theory.
The bad: An overly lengthy Q+A session marked by people insisting on either trying to outsmart Neil deGrasse Tyson on a subject he doesn't (and shouldn't be expected to) know about (like the guy who responded to "I don't know the answer to that" with "Oh, so you're not an expert on that then.."), or using their "question" as an opportunity to talk about how great they are. Classy.
(Photo credit to RGK)