Shadow of the Vampire (2000)

I rec this so hard. Produced by Nicolas Cage, and starring John Malkovich, Willem Dafoe, Udo Kier, Cary Elwes Cary Elwes, Catherine McCormack, and Eddie Izzard.

Mockumentary about the creation of the 1922 Nosferatu: A Symphony of Horror which was a silent German Expressionist unauthorized adaptation of Bram Stoker's Dracula. This is exquisite, hilarious, and horrifying in turns. The plot hinges on movie Director Friedrich Wilhelm Murnau's (John Malkovich) obsession with authenticity that drives him to hire a real vampire and pass them off to the crew as a method actor. Willem Dafoe absolutely nails Count Orlok / Dracula (name changed due to blatant copyright infringement) with a gleefully unhinged portrayal of a vampire playing an actor playing a vampire.

Watch back to back with Nosferatu: A Symphony of Horror (1922) for maximum effect.