The Midnight Movies Collection

When theatres opened their doors in the small hours the night-people gathered: insomniacs; sun-dodgers; loners; stoners; thrill-seekers and intellectuals in search of something creatively stimulating, challenging or boundary-pushing. Collectively, folks bored with mainstream productions.
In response the venues served up B-Movies; schlocky sci-fi and horror; foreign and home-grown exploitation, sexploitation, and blaxploitation; art house, avant-garde and the just plain weird. The venues became places where like-minded people could discover stuff that bypassed most people's radar.
It's classed as a genre by many folks, but I prefer to think of it as an umbrella term that's able to accommodate many different genres. Some examples:

• Akira (1988)
• Alice's Restaurant (1969)
• Altered States (1980)
• The Brain That Wouldn't Die (1962)
• Caligula (1979)
• Candyman (1992)
• Child's Play (1988)
• The Crazies (1973)
• Dawn of the Dead (1978)
• Duel (1971)
• Elvira: Mistress of the Dark (1988)
• Eraserhead (1977)
• The Evil Dead (1981)
• Halloween (1978)
• Heavy Metal (1981)
• The Holy Mountain (1973)
• Mad Max (1979)
• Maximum Overdrive (1986)
• Natural Born Killers (1994)
• Night of the Living Dead (1968)
• Pink Floyd: The Wall (1982)
• Plan 9 from Outer Space (1959)
• Reefer Madness (1936)
• Repo Man (1984)
• The Rocky Horror Picture Show (1975)
• The Street Fighter (1974)
• Videodrome (1983)
• The Warriors (1979)

NOTE: the list is by no means exhaustive; there are many more worthy movies that could've been listed. I've capped it at 28 simply because I have a hard enough time trying to keep the other open-ended Collections up to date.