If you could use only one book to introduce someone to your favorite genre, or you had a chance to make someone who hates your genre change their mind, what book would you choose?

If someone has never heard of your genre and you could pick one book too blow their mind completely, what would it be? Or maybe in the case where someone completely hates your genre you were able to change their mind but you had one book to do it, what would it be?

I'll propose a rule. The book cannot be an outright classic, or can't be something universally praised. I consider that cheating, because everyone I know has enjoyed at least one Stephen King or would be completely floored by Gone Girl. I would like to hear what you guys pick.

What book encapsulates a genre the best in your opinion? What book utilizes multiple or all elements very well?