Not that it’s even one of my favorites, but I was a little surprised to find Rosemary’s Baby absent from this list. As for my personal favorites, surprise surprise, they’re old. 🙂 The Black Cat (1934) is one of those that only really introduces its cult in the third act. It’s a brutal, twisted, but at the same time charming classic, with by far the best Karloff/Lugosi pairing ever. The Seventh Victim (1943) doesn’t make its Satanic cult anything too outlandish or extreme; their philosophy is fairly easy to grasp, their actions and motivations believable, and their threat is in a way most disturbing for its very mundanity.