Avengers and Prisoner have always topped my list, with the original Star Trek not that far behind. Man From U.N.C.L.E. was also a huge fave when I was a kid, and in retrospect, it's interesting to watch it morph and change so much over just three and a half years. In retrospect, certainly Danger Man/Secret Agent gets the points for sustained seriousness of purpose, but they were pretty lucky to have McGoohan to carry it through the rough spots. Wild Wild West was not only a big favorite, but the first TV show I ever watched in color.
And how about I Spy? It can seem kind of precious today, but it was pretty groundbreaking at the time: not just the fact of Cosby being black, but the location work, and the hints of what we'd one day come to think of as Altman-esque dialog.
I'll take Addams Family over Munsters principally because Astin's Gomez was such a weirdly idiosyncratic character: all the Munsters were (admittedly funny) inversions of fairly stock sitcom characters, but Gomez, and his relationship with Morticia, just stood out, even when I was a kid, as something unique. And while rewatchability isn't necessarily an important gauge of artistic merit (to the extent that such a term has any meaning in this context anyway), I've never made it through an entire Munsters episode since I was a kid, whereas I've rewatched the Addamses a few times.
I agree with whoever said Get Smart belonged in its own category; I used to bemoan its late-seasons decline, but have latterly come to appreciate just how amazing it was to keep that concept strong as long as they did.
All votes counted for Twilight Zone, definitely, though when I was young I'd have taken Outer Limits over it in a heartbeat.
And here's the real question: Mr. Terrific or Captain Nice?