Ask HN: Your favorite YouTube channels?

I've been on a YouTube kick lately, and would like some recommendations for your favorite technology/programming/whatever channels. I'm a java developer if that help. Here are some of mine:

https://www.youtube.com/user/GoogleDevelopers

https://www.youtube.com/user/GoogleTalksArchive

https://www.youtube.com/user/AtGoogleTalks

https://www.youtube.com/user/MarakanaTechTV

As you can tell, they're almost all Google talks.