In the past 4-5 years or so, partly owing to COVID, more and more talks have been uploaded to YouTube. In the same spirit as this question by Ryan Williams almost 14 years ago: What papers should everyone read?, what online talks should everyone watch? Be it something that offers a completely new perspective on some problem, a talk where the speaker has electrifying energy, or a nice exposition to a new area for outsiders - what is it that no one should miss out on?
Similar to the Williams post, make sure it's one talk per post and post as many answers as you like.
