But it wasn't really. Twilight Zone, Alfred Hitchcock Presents and Thriller sometimes went into scifi/fantasy territory, and The Outer Limits definitely was.
I always thought that what made it stand out was that it was an American serialised 'adult' scifi. The UK were already on their third year of Doctor Who (which was aimed at kids, but had picked up a bit wider audience) and The Avengers, whilst The Prisoner would come out barely year later.
My two cents about the actual topic? If Quinto sticks around, maybe. Or at least his version will be able to stand on his own like without constant comparisons like Picard eventually did. The way the Internet has changed things of makes it hard to determine based on our own precedent. Maybe if the Internet was around in 1959, there'd be the consensus that Ramon Navarro was the definitive Ben-Hur. Who knows?
Its funny to this day people still compare Kirk to Picard. while Picard is known amongst fans he has never really became the iconic character that Kirk became.
I heard Stewert say on Graham Norton that the average person on the street tended to identify him as a member of the TOS Crew. I think in particular that he had one woman try to tell her husband that he was meeting 'Captain Spock.'
Apparently Stewerts answer was just: "No."
Come to think of it, I'm fairly sure that one of the school friends I dragged along to 2009 thought Stewert
was Captain Kirk. She asked why Pine wasn't bald.