"of all time" is often too strong of a qualifier for me. I would say "talks that I want to rewatch the moment they come to mind."

Charlie Kaufman's Bafta Lecture https://www.youtube.com/watch?v=eRfXcWT_oFs

Gabor Mate, Prisoners of Childhood https://www.youtube.com/watch?v=H9B5mYfBPlY

I consider Bret Victor's inventing on principle a non-technical talk, so yeah that. https://www.youtube.com/watch?v=PUv66718DII

Quel Solaar, on creativity https://www.youtube.com/watch?v=MJmqaWq7PJY