6 sequels:
The Fly 2 | Bride of Re-Animator | Return of the Blind Dead | The Ghost Galleon | Night of the Seagulls | Texas Chainsaw Massacre 2

6 countries:
UK: The Witches | USA: Blood Diner | CANADA: My Bloody Valentine | FRANCE: Diabolique | JAPAN: Wolfguy | ITALY: Monster Hunter

6 decades:
50s: Diabolique | 60s: The Witches | 70s: Wolfguy | 80s: Blood Diner | 90s: Night Terrors | 10s: Raw

6 films from before 1970:
The Witches (1966) | Diabolique (1955) | The Devil Rides Out (1968) | Planet of the Vampires (1965) | The Brain That Wouldn't Die (1962) | At Midnight I'll Take Your Soul (1964)

6 films from the following: Carpenter, Raimi, Whale, Browning, Craven, Tom Holland:
Prince of Darkness (Carpenter) | Village of the Damned (Carpenter) | Shocker (Craven) | Deadly Blessing (Craven) | Evil Dead (Raimi) | Evil Dead 2 (Raimi)

3 people eating people (non-zombie):
Blood Diner | Eating Raoul | Raw

1 Hammer Film:
Countess Dracula

1 Romero Dead film:
Day of the Dead

1 terrible oversight:
Diabolique

2 Tobe Hooper Films:
The Funhouse | Night Terrors

Misc:
Tombs of the Blind Dead | Re-Animator | The Strange Color of Your Body's Tears

Bonus:
IT | IT (2017)

7 rewatches:
Texas Chainsaw Massacre 2 | Prince of Darkness | Evil Dead | Evil Dead 2 | Re-Animator | Day of the Dead | IT