The gang of four show trial was hilarious, while highlighting a serious undertone in the Patterns community. I did find out that it was largely unscripted.
The Squeak talk by Dan Ingalls was great! Amazed quite a lot of people with its rich set of graphics and sound features (the movie/score sync demo was something that I've never seen before, too)
OOPSLA '99 VM Workshop "Simplicity, Performance and Portability
in Virtual Machine Design"
[With links to some interesting Squeak-related papers.
The paper written by Tim Rowledge about the work done at Interval Research is especially recommended – Andreas Kuckartz] http://www.squeak.org/oopsla99_vmworkshop/