Order watched. Not a ranking.

6 countries:
Godzilla 2000
Dead Snow
Viy
Alucarda
Haxan
Deep Red

6 decades: Easily

6 films from before 1966:
The Unknown
The Raven '63
The Raven '35
Black Sabbath
Comedy of Terrors
The Uninvited

6 films whose year ends in '6':
'36 Dracula's Daughter
'46 Bedlam
'66 The Reptile
'76 God Told Me To
'76 Who Can Kill A Child?
'86 The Seventh Curse

6 films featuring work from the following:
John Carl Buechler (Friday Part VII)
Jack Pierce (White Zombie)
Rob Bottin (Humanoids)
Screaming Mad George (Necronomicon)
Lon Chaney (The Unknown)
Carlo Rambaldi (Deep Red)

The 6th film of a franchise:
Friday VI: Jason Lives

1 Reptile Rampage film:
The Reptile

2 women directed films:
Humanoids From The Deep
Dead Hooker In A Trunk

The lowest rated film from the 80s that you can access:
The Alien Dead

1 film where the men and women of the church are having a bad day:
Alucarda

1 Larry Cohen (God Told Me To)
1 Dick Miller (Demon Knight)

1 Classic Universal:
Dracula's Daughter

1 film with Dee Wallace
Cujo

1 film with a black director or predominantly black cast:
Demon Knight
Ganja & Hess

1 film from a Mexican director
Tigers Are Not Afraid

And 1 Tobe Hooper Film:
The Funhouse