Sci-fi is one of the most expansive genres out there, with virtually limitless potential. That said, while there are some excellent shows for viewers of all ages, the genre can be geared towards adults. The best sci-fi TV shows of all time often feature violence, especially when the genre is combined with horror. Even classic sci-fi like Babylon 5 involves some alien romance scenes. Aside from gore, violence, and sex scenes among species of all kinds, there is another aspect of sci-fi that can make it unsuitable for young viewers. Sci-fi TV shows can be uniquely complex, with mind-bending storylines...