7. Martin Landau As Spock
It is rather hard to believe that Leonard Nimoy was not the first choice to play the role. It may have been that he would have taken the part from Landau anyway, but we will never know because Landau took himself out of the running to play Rollin Hand in Mission: Impossible another Desilu Studios production. Landau later spoke about the possibility of being cast as Spock in an episode of the television series Pioneers of Television specifically on Science Fiction. It was broadcast on PBS in 2011, and Landau said:
I turned down Star Trek. It would've been torturous. I would've probably died playing that role. I mean, even the thought of it now upsets me. It was the antithesis of why I became an actor. I mean, to play a character that Lenny was better suited for, frankly, a guy who speaks in a monotone who never gets excited, never has any guilt, never has any fear, or was affected on a visceral level. Who wants to do that?
Nimoy had known Roddenberry from appearing on The Lieutenant, and got the part. However, this wasn't the only different casting that could have occurred for the pilot of Star Trek the producers also sought Lloyd Bridges for the part of Captain Christopher Pike, but he turned it down following the then recent failure of his film Rocketship X-M.