The first in what will be a series of Inspector Gadget Voice Compares, the series gives us a unique set of voice compare opportunities thanks to producing three versions of the series pilot as well as switching production studios between season one and season two of the original series.
As for Gadget, the first actor to don the role was Gary Owens who voiced him in the first version of the pilot episode. The powers that be decided they wanted to go another direction and shot a second version which featured Jesse White doing his best Don Adams impression, although no footage is currently available of it. Finally the studio decided in between the pilot episode and episode two that instead of having someone imitate Don Adams, why not just have Don Adams, himself voice the role, which he did from episode two on.
There is even a rumor that Frank Welker voiced Gadget over a few lines in the pilot episode in order to explain away Gadget's early moustache, and we have since the creation of this VC been able to confirm this rumor!
Finally, after Don Adams stopped voicing Gadget, Maurice LaMarche has taken on the role in a variety of projects, such as Gadget and the Gadgetinis.