Going back to Tuvix, I really liked the way the writers presented the situation. They didn't make one side of the argument look more "right" than the other. On one hand we had Janeway and the crew, who we were supposed to like and care about, executing Tuvix in order to save the lives of their friends. And, on the other hand we had Tuvix, an innocent lifeform who did not deserve to die, and who I felt genuinely sorry for when he did. They really left it up to the viewers to decide for themselves who they supported, rather than being extremely preachy like TNG very often was.