Stealth fighters
What I found amusing about the F-117 was the many "guesses" that people were making about it before its actual configuration was revealed. I remember the plastic model that came out of the "F-19" stealth fighter. Educated guessers formed the plane in smooth curves, which is what most people figured would result in a reduced radar signature. I certainly would never have predicted the angular, faceted plane that actually was being built.
The mythical F-19.