Because you like DEATH in Discworld
Gruff and sarcastic, Detective Harry Dresden use unconventional ways to track down perps, including using magic and the supernatural. See them in The Dresden Files.
Sabriel is smart enough to understand the dangers that await her and brave enough to face them anyway. See them in Abhorsen Series.
John Yossarian is trapped in irony as he must be insane to leave the war but if he does try to leave, he'll be deemed sane and will be forced to stay, See them in Catch-22.
Combining an innocent face with an insatiable bloodlust, Eli recruits friends to join the vampire way of life. See them in Let the Right One In.
A champion of chivalry, Don Quixote is dutifully bringing good to the world—even when others think he's out of his mind. See them in Don Quixote.
Jean-Baptiste Grenouille may have a phenomenal sense of smell, but he has a weak sense of morality. See them in Perfume: The Story of a Murderer.
A bureaucrat in the Land of the Dead, Manuel Calavera is a jaded, sarcastic loner who just might have a hidden heroic side. See them in Grim Fandango.
Marv is a brutish but principled thug who'd be right at home on an ancient battlefield. See them in Sin City.
Arthur Dent is an incredibly normal man on an incredibly abnormal adventure. See them in The Hitchhiker's Guide to the Galaxy.
Sarah Kerrigan is pretty much the Queen Bitch of the Universe. See them in StarCraft .
Gregor Samsa is an ordinary man in an abnormal predicament. See them in The Metamorphosis.
Raz is a 10-year-old boy who mostly stays in his own head, which makes sense since that's where he is strongest. See them in Psychonauts.