Movies that initially received an X or NC-17 rating from the MPAA, whether they kept it or not.
http://www.ranker.com/list/movies-originally-rated-x-or-nc-17/but-chickens-double-d,
Casino
Clerks.
Cliffhanger
Dawn of the Dead
Dressed to Kill
Midnight Cowboy
Monster's Ball
The Doom Generation
The Doors
Total Recall