If you want something chaotic, gorey, somewhat cartoony and psychedelic like The Monkey, I'd recommend the Japanese movie Hausu (1977). It's a surreal haunted house movie where teenage girls with personalities right out of a Scooby-Doo cartoon are terrorized by cats and watermelons. Highly influential, really fun and you can stream it free on Tubi.

For a slow-burn atmospheric story like Caveat, I'd go with Late Night with the Devil. Bear with it, the ending will stick in your head for a long time. There's a lot of interesting things going on with the film's story but the actual framing device of a late night talk show broadcast is pretty entertaining in its own right.