HAMDig

I recommend investing 2-4 hours to watch some of the most interesting set of talks, there is a lot of interesting history too:

Here's the first part:
https://www.youtube.com/watch?v=3V_u2vEY2CY
Technically, this is Part 2 of 3.

Here's the second part:
https://www.youtube.com/watch?v=ciX5Jjn_Ipc
Technically, this is Part 3 of 3.

Here's the third part (that I consider optional):
https://www.youtube.com/watch?v=qOV7jab67B4

Gary also put together a condensed version:
https://www.youtube.com/watch?v=Bwk-r8AJBR0