Andreas Antonopolous is the most common choice because he knows the stuff pretty good at a technical level and is well spoken and can make things viable to watch for longer periods of time, but if you want to learn from a real expert then I recognize that you watch lectures by Adam Back. The guy may not have the speech skills of Andreas but he is an actual developer of Bitcoin so he knows more at a technical level. Greg Maxwell is pretty good too but I can't find much stuff from him on video. The elements/sidechains video was good.

https://www.youtube.com/watch?v=9pyVvq-vrrM