I had originally meant to include multiple serial killers in this blog post, but then I found that all the books and movies were based on just one: Ed Gein!
Ed Gein was a serial killer living in Wisconsin who committed several murders of women and made gruesome items out of their skin and bones, including clothing and household objects. He also did some graverobbing. Gein confessed that after his mother’s death he had begun to make a “woman suit” so he could become his mother. He was pronounced unfit to stand trial and spent the rest of his life in a psychiatric facility.
Clearly, there’s a lot of work with here, and the writers of the following books and movie scripts had a field day with it.
Books:

Psycho by Robert Bloch takes the idea of a man who is so distraught by his mother’s death that he kills in an attempt to become her and turns it into this horror classic.

The Silence of the Lambs by Thomas Harris has a character based on Ed Gein: Buffalo Bill, the serial killer who the FBI eventually learns is making a suit out of skin. Hannibal Lecter, the more famous character from this book, also bears some similarities to Gein.

Child of God by Cormac McCarthy might not be a full-on horror novel, but McCarthy can get really dark. This one was not directly based on Ed Gein, but the main character is into necrophilia – so much so that he begins killing.
Movies:

Ed Gein (2000) aka In the Light of the Moon is not the most factual biopic out there, but it is the most closely based on facts of everything on this list.

The Texas Chainsaw Massacre (1974) bases the main villain, Leatherface, on Ed Gein. Leatherface and his family are also responsible for grave robbings and other atrocities similar to those of Gein’s.
House of 1,000 Corpses (2003) might not have been directly based on Ed Gein’s crimes, but director Rob Zombie was inspired by “The Texas Chainsaw Massacre.” In this case, the patriarch of the murder family is the one wearing the human skin mask.
Which Ed Gein incarnation is your favorite?