My favorite guest of honor speeches have been anecdotal -- ones that share incidents in the life of the writer that were funny or touching or surprising, or taught them something about their craft.

My least favorite guest of honor speech was basically a manifesto about The Singularity. Of course, if I liked the concept better I might have been more interested, but it felt a little like going to a birthday party and finding out, once you're there, that the birthday girl is trying to sell you Tupperware.