i've watched loads so here are some comments!
the fairlight one was the first, and is amazing.
then i started hoarding them as downloads.. i've prefixed their filenames with what party they're from.
assembly 2005-seminar-freax_history_of_the_demoscene_by_tamas_polgar.avi (have read the book already)
Martti Nurmikar stuff..
warning -> assembly-2009_871_Demo_Programming_for_Beginners_h264_1856kbit.mp4 pretty much same as the 2008 one so choose one or the other
this one is the next generation of the above, more in depth and different enough to warrant viewing.
(note: this is also the one raizor embedded above, it might be worth watching one of the others first)
this one is great from the angle of art/presentation rather than a technical standpoint, basically from ASDs coder
(this is also very in line with my way of thinking which i liked)
a talk by a guy from Unity about why they shoot for what plaforms and O/Ss they do, basically showing that at the time this was made most of the world was running directx 9 despite lots of hype about directx 11.
quite an interesting one about how indie devs are accidentally innovating due to their circumstances and examples of innovation in low tech/no gfx indie games