Late Night with the Devil
Pretty great horror comedy set in the '70s on a late night talk show set. It plays out pretty much how you'd expect, but it's still really enjoyable. David Dastmalchian does a great job; this is the first lead I've seen him play. It borrows a lot from other cult classics like Ghostwatch as well as the obvious stuff like The Exorcist, and has plenty of overt references to stuff like Bohemian Grove, Gnosticism, Anton Lavey, etc.
Ghostwatch
Felt like making it a double feature after watching Late Night... If you haven't seen it, it's a BBC special from '92. It was a paranormal spinoff of their Crimewatch show, using the same format, hosts, etc. It was a proto-Blair Witch undisclosed found footage show, and people lost their minds. The ways they fuck with the audience are pretty genius.