high

Talks speeches podcast etc...

http://dolectures.com/

http://99u.com/videos

http://www.feastongood.com/conference/past-speakers/ (use Vimeo)

http://www.thersa.org/events/video

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

http://www.khanacademy.org/ (amateur videos, audio quality not topnotch)

http://www.academicearth.org/ (a bit like uni lecture recap)
Academic Earth aims to provide everyone with the opportunity to earn a world-class education by offering free online classes and online learning tools. 

http://topdocumentaryfilms.com/all/ (documentaries collected on the internet I think)

http://edge.org/videos (with transcript, but can be too specialised)