The Exorcist (1973)
Warner Bros—courtesy Everett Collection

A sadistic burn victim, a cannibalistic psychiatrist, and several mask-wearing, knife-wielding psychopaths: they'll haunt your dreams, and shore up scary big earnings at the box office.

The low-budget horror flick is a perpetually popular genre, with some of the scariest movies ever produced receiving little to no studio backing. The Blair Witch project was produced on an initial budget of just $25,000 (it shot up another $500,000 or so once Artisan Entertainment bought it) and earned more than $140.5 million domestic. The original Paranormal Activity was shot for just $15,000, a number it easily eclipsed on its way to a $100 million-plus box office take.

Perhaps it's little surprise, then, that keeping with the low-budget theme, the first film in five of the eight franchises on this list were produced for under $2 million. The other three cost $12 to $15 million and enjoyed enormous profit margins. Though budgets steadily increased with each new film, all of these series remain incredibly profitable.

Adjusted for inflation, The Exorcist is the highest-grossing horror franchise of all time, and its namesake 1973 film is also the top-grossing single horror film. It brought in $193 million domestic, the equivalent of about $860.76 million today (for reference, the current gross of this year's mega-hit Jurassic World is $651.5 million).

The final numbers used in the slideshow are the domestic box office grosses, adjusted for inflation according to Box Office Mojo.