Johnny mentioning The Devil's Rain reminded me that there are loads of 70's and early 80's B-movies films, which while no masterpieces, are comfort films for me. These are some of the films I spent my pocket money to see at the time:
The Car (car possessed by the devil runs down the hapless denizens of a small desert town),
Kingdom of the Spiders (starring William Shatner, his toupe and hundreds of pissed off arachnids),
Bug (pyromaniac cockroaches as the next evolutionary step),
Burnt Offerings (Oliver Reed, Karen Black and Bette Davies in a cut price haunted house flick which gave me nightmares),
the It's Alive! films (especially It Lives Again!, the second one),
Alligator (written by indie maverick John Sayles, this has some snappy dialogue)
Empire of the Ants (real estate harpy Joan Collins gets brainwashed and then eaten by giant ants)
The Manitou (during the climax a topless Susan Strasberg floats through the fourth dimension in her bed while shooting laser beams from her hands at an evil Native American dwarf deity while channeling the spiritual energy of some clunky 70's computer. Pure trash gold!))