I typically like the most scientific ones rather than the touchly-feely ones. There was one about stock market crashes which I found really interesting . here it is <a href="http://www.ted.com/talks/didier_sornette_how_we_can_predict_the_next_financial_crisis?language=en" rel="nofollow">http://www.ted.com/talks/didier_sornette_how_we_can_predict_...</a>
Haven't kept up very well, so there might be more recent ones that best these, but from what I remember...<p>The funniest while still being somewhat interesting was Ze Frank. The most interesting while still being really funny was Sir Ken Robinson. Lessig's talk about Sousa was also pretty amazing.
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Are we allowed to suggest our own? :)
<a href="https://www.youtube.com/watch?v=MY3XWYr726I" rel="nofollow">https://www.youtube.com/watch?v=MY3XWYr726I</a>
</shameless_plug><p>I'll get my coat ...