I've read a handful of his work, but The Executioner's Song is by far my favorite. It is probably in my top 10 favorite books ever.
It is creative nonfiction before there was a term 'creative nonfiction.' It is the story of Gary Gilmore, who in the 70's randomly went into a gas station and made the attendant lie down on the floor and then shot him in the back of the head. There wasn't really any reason. He just did it.
He was also the first person to fight for his own right to be killed. He was on death row and they wouldn't kill him and he fought for them to kill him.
Mailer writes the story in simple, nice sentences and somehow encaptures the whole thing with this weird pull that makes you not able to stop reading it.
It is 1,056 pages and I read it in I think 3 days.
It is also the loose basis of the film Cremaster 2 by Matthew Barney, which has some awesome images (though most of the really good ones I can't find online).
I'm not one to romanticize dead icons, but you should read this book.
