I really enjoy giving a well thought out high value, well executed, keynote speech. That's probably a tie over for being a policy debate coach.
As I work with clients, I often help them refine their business changes for each competition often with big bucks on the line.
As somebody who has both pitched and hosted business pitch competitions. I've seen it from both sides.
This document created by the Michigan SBDC in collaboration with the Seattle Alliance for Angels is a great overview on how to create a solid pitch. It is frozen and 16 so it's a bit dated and it requires a presentation go along with it, but it's still worth a peek.