5. Inspector Gadget: Dr. Claw Is The Real Uncle Gadget
Here's a classic; according to this theory the Inspector Gadget that we follow throughout the series is a robotic clone (if such term exists) of the real Inspector Gadget. What happened to the real one, you may ask? Apparently he had an awful accident, so the police replaced him with a robotic version. Meanwhile the real Inspector Gadget, furious at his replacement vowed revenge against the man who took his life away from him. It gives a really dark turn to an otherwise childish and dumb Saturday morning cartoon, and the weirdest thing is that you can actually see something like that happening in the series. Maybe not as dark as the theory puts it but it could lead to a very interesting episode. Even if you disagree with this theory you've got to admit; it would've made for a much more interesting reveal of who Dr. Claw really was.