He played in westerns before Star Trek, notably Gunsmoke. He certainly helped to make Trek the classic that it was as Spock. The series was way ahead of its time. I certainly enjoyed it at the time, and afterwards. I've probably seen each episode, seriously, ten times over the years. The characters from the series became household words. Kirk, Spock, Uhura, Sulu, Scottie, Bones, Chekov. They all became typecast to a certain extent, but William Shatner was most successful in breaking from the mold after the series. Clearly, though, the series would not have been the same without Spock. RIP, Leonard Nemoy