I think Star Trek was a good progressive show in the sense that it showed a post-racial society as a normal thing. It also promoted ideas like the value of people over profit and material goods, that violence (or even peace) is not always the answer, the importance of science and better understanding your world (even if the science presented was iffy), not over relying on machines and computers, among other things. It was the values that it preached that make it special, not because it might have had the first interracial kiss on TV. It didn't always get it right, especially with regard toward its treatment of women, but I think it tried its best to address the social and political issues of the time without getting too ham-fisted about it.