If you enjoy these, you should also check out the videos from Startup Bootcamp on 9/11/2010 at MIT.
Chris Wanstrath (Github)
Mick Mountz (Kiva Systems)
Ayr Muir (Clover Food Labs)
George Bell (Excite)
Bob Metcalfe (PARC, 3com, ethernet, etc.)
Bill Clerico (WePay)
James Lindenbaum (Heroku)
Alexis Ohanian (Reddit and now YC ambassador)
Stephen Wolfram (Wolfram Alpha and Mathematica)
Kevin Hale (Wufoo)
Ric Fulop (A123 Systems)
David Cancel (Performable, Compete)
There are also more archived talks from previous years.
I liked Ron Conway, Brian Chesky and Tom Preston-Werner the most. But it's kind of hard to choose overall.
pg's state of the funding was very interesting but can be found in writing on his site.
Adam D'Angelo had some good insights (if you're not sure yet, go work for a startup; at first, it's ok if it doesn't scale) but his presentation was so-so.
Mark Zuckerberg was interesting though I'm not sure you'd get as much good useful bites as others.
Finally the Imeem's CEO (whose name I can't remember right now, sorry) had a great presentation and delivery. If you were not thinking about doing a music startup, the insights are somewhat limited. Very fun guy though.
i really liked brian chesky's talk on airbnb. very unique story that teaches you to never give up and get close with your customers. 3rd video down from the top
http://www.youtube.com/startupbootcamp