I came across this by chance, as I don't usually pay attention to "GDC rants."
Chris Hecker, the man behind Spy Party, took part in a rant at GDC this year and from the videos, it looks like it was one to see.
It wasn't verbose--little was said by Hecker--and it wasn't what one might call a rant, but it was still effective. Hecker used video footage to challenge the preconception that games will be improved (or have been improved) thanks to newer, more highfalutin' technology. Again, it was very effective I think.
The above video is a recording of the GDC rant with audience reaction. It starts at the 4:05 mark.
This video is just the presentation that the audience was watching on the projector.