Some of the best movies of all time have been rated R by the Motion Picture Association, but critical success is no guarantee of profitability, especially since some potential viewers are restricted from watching such films. (The rating means that those under 17 can be admitted only with a parent or guardian.) Nonetheless, some R-rated efforts end up making considerable profits – especially those with low production costs. (While some of them may have had high production budgets, these are some R-rated movies that broke the box office.)

To determine the most profitable R-rated movies of all time, 24/7 Tempo reviewed data on box office receipts and production budgets from The Numbers, an online movie database owned by consulting firm Nash Information Services. R-rated movies were ranked based on the ratio of worldwide ticket sales to production budget, or the return in box office receipts for every dollar of production budget invested in the film. Only movies with at least $3.5 million in global ticket sales were considered. Cast credits are from IMDb, an online movie and TV database owned by Amazon.

Click here for a list of the most profitable R-rated movies of all time

Of the 10 most profitable films on our list, eight are horror or thriller movies. A lot of things can go wrong with a horror movie – laughable dialogue, cheesy special effects, weak story, bad casting – but when movie makers get it right, fright flicks can obviously deliver at the box office.

Two examples are evidence of movie makers updating the genre with a mockumentary style and a topical spin. “Chernobyl Diaries” is about American travelers taking an extreme tour of the former nuclear power plant in Ukraine, while “Unfriended” is the story of chatroom friends terrorized by a supernatural force using the social-media account of a deceased friend.

Of the 50 movies on our list, half are either horror flicks or thrillers. But white-knuckle offerings aren’t the only box-office boffo films. Reliable rom-com fare such as “Pretty Woman,” “Swingers,” “The Brothers McMullen,” and “Lost in Translation” were big winners, as were the more raunchy comedy fare like “National Lampoon’s Animal House,” “Porky’s,” and “Kentucky Fried Movie.” (Here’s a list of the best R-rated rom-coms of the past 50 years.)