Lost in Space
debuted when I was 14. I liked the hardware of the ship, the Robot, the laser guns, the Chariot, and the retro-style cliffhanger endings. And John(ny) Williams' background scores.
But by the time of the 11th episode ("Wish Upon a Star"), I realized the focus was shifting to the nincompoopiness of Dr. Zachary Smith and quickly got disgusted with it.
There was a TV Guide article about the series during its run, and I did think it was sort of cool that Billy Mumy (3 years younger than me) had made his own decision to be in it (rather than his parents), because he liked science fiction.
Bill was known as the creepiest kid on television, thanks to his appearances on The Twilight Zone