For some conferences, I perform a duet with a guest speaker or perform the link between multiple speakers. For most conferences I recommend a blend of activities across the conference with spoken presentations just a start and ending highlight.
From personal experience I can recommend a wide variety of people to kick start the conference or individual days and lead into entertaining activities. A good investment in this year's partner program will lead to significant returns across subsequent years.
Send me a description of your conference program for a free recommendation on interesting, entertaining, useful partner programs.