Das Omen

Classic. You bring the devil to your film and do it well, then you're competing with The Omen as much as you are The Exorcist, which to this day are arguably still the gold standards when it comes to Beelzebub showing up on screen.

Also a benchmark for creepy music adding additional creep: Gregorian chants start as a murmur, and built to a ratcheted intensity that simply put the film way over the top in the best possible way. This was 1976, remember, so what you'll get - and I'd say as an added bonus - is the very Seventies look and feel that movies had during this very unique era.

When Peck exhumes the grave, and when the film closes with young Damien smiling, the hair on one's back shoots through the roof. The Omen is simply all-time.