6. Star Trek: Deep Space 9, "Rejoined" - Trek's First Same-Sex Kiss
Much like "Plato's Stepchildren", "Rejoined" had some caveats to its kiss. The characters involved were once in a heterosexual relationship. I say once because the characters in question are members of a race with symbiotic entities inside of them, entities that retain memories and personalities of past lives. However, on their world, the resumption of such a relationship in later lives is considered extremely taboo. The kiss itself may have caused more controversy than the one in the Orginial Series. For one, a southern affiliate cut the kiss from it's broadcast; for another, one of the writer's mothers was absolutely scandalized. then there's this story.