Confreaks is great. The youtube page linked to is nicely organized, and looks to get more attention that my pointers, but three other resources are

* The Confreaks homepage at http://confreaks.com/

* The Confreaks listing by conference at http://confreaks.com/events

* The list of recently added videos at http://confreaks.com/videos

The last one is a bit hidden, as you get to it by clicking on Search on the main page