I haven't seen it, but I suppose that qualifies Terminator: The Sarah Connor Chronicles, since it is a TV series after all? What about Babylon 5? Well, I could make that argument up until The Lost Tales, anyway. The Vorlon (or other First Ones) advanced tech seem to be the root of anything perceived to be supernatural on that series. Of course, the "demon" in The Lost Tales doesn't fit that explanation. It's nearly presented as a demon. Yes, there are pseudo scientific explanations that can be made about it (and have been on these boards), but that's not really found in the text of the episode.