I picked up Richard Laymon's Madman Stan and Other Stories and simply could not put it down. The writing is ok--it's not the most lyrical prose you'll ever read. But the content is amazing. Laymon is a superior creative talent. The title story is pretty fine, but my favorites include "The Maiden" (a nice twist on the teenage rite of passage tale), "The Champion" (a macabre tale of possession and the cruel hand of fate) and "Bedtime Stories" (a little ditty that would have made a fine episode of Spielberg's Amazing Stories).
Laymon's writing is filled with awkward sexual tension and gruesome plotting. His protagonists, on the whole, are decidedly immoral. Laymon enjoys goading the audience into rooting for a character to get out of a horrific situation, only to then push that character into committing an act of depravity (often unprovoked). If there is a common thread in these stories, it's that people do bad things to each other.
If you liked The Collection, by Bentley Little, you'll enjoy this book. While not in the category of King's Nightmares and Dreamscapes or Lansdale's Mad Dog Summer and Other Stories, this is a set of stories that will compel you to hit the word processor and generate some of your own dark work.