A few channels,  dozens of speeches, hundreds of learning opportunities.

1.
https://www.youtube.com/user/crashcourse
https://www.youtube.com/watch?v=wyzi9GNZFMU (virtually verbatim subtitles!)

2. 

https://www.youtube.com/user/bigthink
https://www.youtube.com/watch?v=MbnFJVgBcw0 (whimsically untrustworthy subtitles)

https://www.youtube.com/watch?v=w8SOQEitsJI (low reliability)

3.

https://www.youtube.com/user/TEDxTalks
https://www.youtube.com/watch?v=H2vN2QXZGnc (reasonably trustworthy subtitles)

4.
https://www.youtube.com/user/TEDEducation
https://www.youtube.com/watch?v=esPRsT-lmw8 (reasonably reliable)

This website's almost too good to be true. It's packed full of sound investigative reporting. This is as serious you can get by today's TV journalism standards...You'll be able to find documentaries on almost every topic imaginable on this site. And to top it all up, all transcripts are available too!!! I just can't believe this is free!!!

http://www.abc.net.au/4corners/episodes

For those wanting to have a more in-depth insight into the (CEFR) Common European Framework of Reference  for Languages (CEFR).
http://www.coe.int/t/dg4/linguistic/Source/Framework_EN.pdf