A horror thread, huh?
Well, I have time to share a few thoughts:
While I think The Cabinet of Dr. Caligari is marvelous, technically the first acknowledged horror film is The House of the Devil by Georges Melies (one of the fathers of film) way back in 1896. It's on YouTube, see what you think.
While we're talking old horror, 2022 is the 100th anniversary of Murnau's Nosferatu and that's still a damn good movie a century later. The 1910 version of Frankenstein is brief but still very good.
I like the classic Universal monsters until they decided to water them down and stick Abbott and Costello into the movies (no thanks!). I'm a fan of Karloff, Lugosi, Chaney and Chaney Jr.
I'm a Hammer Horror fan
I'm an Asian horror fan - the original Ringu is still great.
I always love me some George Romero, The Exorcist, Jaws, Rosemary's Baby, etc...
Books? Yeah, I'm a fan of the classics. I recently re-read Stephen King's It for maybe the third time since it first came out and I enjoyed both movie versions.
Kim Newman's Anno Dracula books and his other works is always enjoyable.
Well, this is a big topic and there's lots to talk about.