1. Killer Klowns from Outer Space (1988)
If there's a Casablanca of killer clown movies, this is it. Often dismissed as a bad movie because of its goofy title, this is actually a very good b-movie homage/parody/throwback that succeeds on its clever screenplay, funny set pieces, weirdly creepy murders, and some truly eye-popping set design, costumes, and special effects. It may be a little cheap in some regards (and some of the acting isn't exactly Streep-like) but there's more than enough creativity and good humor to be found in this tale of interstellar clown monsters who invade a small town.
Where to watch it: Streaming on Amazon Prime and Hulu. But you should own this one by now!