Author: Stephen King
What is it: An author, Paul Sheldon, is involved in a car crash and is badly wounded. (Un)Luckily he's saved by his number no.1 fan, Annie Wilkes, an elderly nurse who brings him to her secluded home where she treats him with medicine, food, care etc. In return, Annie asks Paul to do something special for her, that is, to write a very special book, just for her, all about her favourite character from his novels. One he had killed off and now has to bring back to life. Because if he doesn't, she gets upset, very upset, and does things to him that are best left not to be said.
As sick as it sounds, I like reading how Annie inflicts pain on Paul and what he does (or tries to do) as a counter-measure. I just read what is surely the most detailed sequence thus far (the smell). *shudders*