Played By: Dean Stockwell, Tricia Helfer, Lucy Lawless, Grace Park, Callum Keith Rennie, Matthew Bennet, Rick Worthy

So often in science fiction, fear of an alien race is instilled in the audience by creating something truly unfamiliar through grotesque make-up and prosthetics or monstrous CGI designs. Ronald D. Moore took the opposite route when creating his Cylons for the re-imagining of Battlestar Galactica. These aliens look just like us. They could be walking among us and we would have no idea.

Though Tricia Helfer's sensual yet deadly portrayal of Number Six is most beloved among fanboys, the various personalities of the Cylons make them a truly compelling group of villains when viewed. From the stark, harsh violence of Number One (Dean Stockwell) to the unhinged, mercurial behavior of Number Two (Callum Keith Rennie), the Cylons run the gamut of villainous personalities.

Despite their far superior forces over the humans, they never feel infallible. Their humanity, both externally and internally, makes them some of the best villains in TV history.