Here's my wish list (and yes, I know most of these will probably never happen but I can dream )
David Hasslehoff
John DiMaggio (any one from Futurama really)
Frank Welker
Peter Cullen
Jonathan Davies (Jonathan Creek)
Mark Dacascos
Christopher Lambert
Jet Li
John Cleese
Eric Idle
Michael Palin
Terry Gilliam
Anyone Buffy/Angel/Firefly/Serenity related
Anyone from Bones/Stand-Off