I am a big fan of TED Talks, they have created a list with the Top 10 TEDTalks. My favorite among those ten is Jill Bolte Taylor talking about My stroke of insight.
You can view the talks by Themes, Speakers or the Talks List. And while you are there, sign up for their newsletter and get information when new talks are available.
This was originally posted at Forty Plus Two, another blog of mine.