When I say 'supernatural', I don't mean the television show Supernatural, but all TV shows with a super natural theme (e.g. magic, mythical creatures, aliens, superheroes, etc). Which is your favourite?
My favourite supernatural sci-fi series is The X-Files. As well as the search for aliens, I love their monster of the week episodes. The liver-eating mutant, Eugene Victor Tooms, from the first series is unbeatable. I also love Roswell, which is about a group of teenage aliens trying to find out about were they belong, while avoiding alien hunters who want to kill them, and Charmed, a series about three/four witch sisters protecting the world against evil.
To a degree, the age of a show doesn't bother me. I can't really do shows that were 70s and earlier, but anything 80s and up is fair game. There was something about the acting style pre-1980 that didn't do it for me, but I loved a lot of 80s stuff, the original Battlestar Galactica, the A-team and Knight Rider were huge favs when I was a kid. I haven't rewatched them since my childhood, but it is definitely on my to-do list.
The show Supernatural is actually one of my favourites, though it gets a bit nasty and misogynist as it goes on. I have a soft spot for the X Files. I also enjoyed Buffy, Angel, Pushing Daisies, Dead Like Me and Sanctuary.