DeForest Kelley was the oldest member of the TOS crew. He described himself as shy and the only cast member to not engage in feuds with the others, as well as the only one not to write a memoir. Even though he never attained the same fame as Shatner & Nimoy, he was thankful that he was the only one of the three to stay married. <3 (source, wikipedia)
Star Trek: Deep Space Nine Dealt with issues of spirituality, the shades of good and the shades of evil, and the idea of what/who constitutes the "other." The cast was incredibly diverse, as far as race, age, ethnicity, etc., and the female characters were some of the strongest women ever on TV.