That thorn should be in your side. Anything you find stuck in your back should make you consider that your popularity in the Mod-Squad might be waning. Generally I would suggest looking to see if the series in question attempts to explain the fantastic powers/occurences with scientific theory. Trek and Firefly clearly do this; X-Files and the whole Superhero genre are far more murky. Buffy is clearly Fantasy, but Dark Angel is completely Sci-Fi. Medium I would say is Fantasy, while Scanners is Sci-Fi. I don't know how I would class someone like Batman, who is neither Sci-Fi or Fantasy himself, but deals with both.