6 sequels:
Psycho II | Halloween III | The Exorcist III | Hellraiser III | Return of the Living Dead Part II | Fright Night 2

6 countries:
Netherlands: The Vanishing | England: Peeping Tom | Austria: Funny Games | Japan: Cure | Italy: Inferno | USA: The Hitcher

6 decades:
50's: The Blob | 60's: Carnival of Souls | 70's: House | 80's: The Keep | 90's: The Resurrected | 10's: Raw

6 films from before 1970:
1931: Dracula | 1931: Frankenstein | 1933: The Invisible Man | 1958: The Blob | 1960: The Brides of Dracula | 1962: Carnival of Souls

6 films from the following: Carpenter, Raimi, Whale, Browning, Craven, Tom Holland:
The Thing (Carpenter) | Prince of Darkness (Carpenter) | Frankenstein (Whale) | The Invisible Man (Whale) | Dracula (Browning) | The Hills Have Eyes (Craven)

3 people eating people (non-zombie)
Raw | Ravenous | Blood Diner

1 Hammer Film
The Brides of Dracula

1 Romero Dead film:
Day of the Dead

1 terrible oversight:
Diabolique

2 Tobe Hooper Films:
Spontaneous Combustion | Lifeforce

Extra Credit:
It (2017)

Only 4 rewatches: The Thing, Prince of Darkness, Day of the Dead, and Lifeforce