This QOTW is made for me
I bloody love books.

Mild warning - this answer contains no jokes, no witty word plays and doesn’t strictly stick to the question as no single book actually changed my life (although several probably saved it whilst being used as spider defence shields).

Anybody who doesnt like books is just thicky scum. This is perhaps slightly on the harsh side but who cares? Books open up whole new worlds; with a bit of imagination and a good book you can explore deserts, hunt down pablo escobar, learn that the orangey bit in jaffa cakes is actually made from apricots and personally win the battle of Britain. But no, you cannot be a speccy baby wizard at boarding school unless you're under the age of 15. – ITS FOR KIDS.

Again in contradiction of the instructions, here is my list:

Horror books
Stephen King is overrated. The true master is Dean Koontz. I challenge anyone to read Watchers, at home, alone, at night and not want their mum.

Travel books
A great genre. The most popular authors - Bryson et al. are good but for the best reads go for the one off authors who have done something special: spent a year digging for gold, completed the south korean riot police 1 year martial arts course, become a professional poker player etc. The point is that these books are largely written by one-book authors with something amazing to talk about. Some are poor (Jupiters travels), many are great. Go find 'em

War
Huh, what is it good for? Books.
A couple of my favourites are Steven Pressfield, Tides of War (the book 300 is based on), Mark Bowden, Black Hawk Down (masterful). War books about real incidents, or based on real facts with the story added on top tend to be the best.

Politic thrillers
Tom Clancy. He wrote about a suicide pilot flying a 747 into the white house MANY years before 2001. Realistic, very well researched and deeply immersing.

'Scientific' books
Jared Diamond - 'Collapse' and 'Guns, germs and steel' should be in everyone’s library. Other valuable reads include: In bear country, Dont run whatever you do, call of the wild (not about the dog) and the undercover economist, but there are many others.

Other great authors everyone should try include: Terry Pratchett for his observations on life, Douglas Adams - the biscuit sketch in the hitchhikers guide is genuinely laugh out loud funny, Bernard Cornwell's Sharpe kicks some French derriere in true swashbuckling style and Romeo Dallaire's account of when he was in charge of the UN forces in Rwanda will move most people close to tears.

Favourites:
1) Hitchhikers guide
2) Doug Standon, In Harms way. The US cruiser that delivered the bomb, as told in Jaws.
3) One of many by Wilbur Smith

Go read people.

Oh, and avoid anything described as a classic. Dappled autumnal leaves glowing golden in the early morning sun…. ahhhhhhhhhhhhhhhhh. Books are not about poncy literature. And please, just because 10 trillion pounds has been spent on the marketing of a book it does not make that book good. You arguing that it is, actually, good tends just to highlight your media whoreishness: Dan Brown, Rowling, the bible etc
(Digstar fu#king loves biscuits, Sat 17 May 2008, 9:28, 7 replies)

*click*
Dean Koontz - tick
Tom Clancy - tick
(TheWeeWitch hasn't been here much recently .., Sat 17 May 2008, 10:23, closed)

Hmm.
I read Watchers....
It scared the fucking shit out of me.
I read it, at home, alone, on a night when my parents were out of town.
STUPID IDEA!!!

Dean Koontz is brilliant. But I think you should read IT if you want a scare. I used to love clowns. I'm terrified of them now.

You have good taste. *tick* *tick*
(Poppet some assembly required., Sat 17 May 2008, 11:26, closed)

Here's something Koontz wrote for Amazon.com
Ten thousand years before the first word of history was written, the first audio book was created by Og, brother of Nogg and Plogg, son of Vog and Noog, grandson of Zogg and Heather. Og was a born storyteller frustrated that paper had not yet been invented. He wrote his first book on slabs of wood, burning the words and pictures into the surface with sharp pieces of stone superheated in fire fed by Wooly Mammoth fat. He is credited by some with inventing the words "hot," "ouch," "S***," "***k," "D**n," and "************," as well as the exclamation point.

Because he was both writing and manufacturing his novel, Og was a writer-publisher, the first known hyphenate. Also being one of the first to suffer from multiple-personality syndrome, the writer in him hired another aspect of himself to serve as his agent, which deeply annoyed the part of him that was a publisher. In vigorous negotiations conducted with rocks, clubs, sharpened Mammoth bones, and primitive squirt guns full of blinding viper venom, Og the Agent won for Og the Writer an advance of 120 dried apples, three dead squirrels, a pretty yellow pebble, and one rotting but still flavorful haunch of moose.

With high hopes and with dreams of wealth, Og the Publisher acquired a formidable stack of wood, hundreds of sharp pieces of stone, and gallons of Mammoth fat to feed the publishing fire. In just five months, he made eleven copies of this epic story, which led to frequently scorched fingers and the invention of the dubious word "s***f**," and the now seldom used "q***t***uw***d." He launched the book with the first publication party. The event was such a hot ticket among cave-dweller society's movers and shakers that even the Missing Link showed up.

Sadly, all the dreams of Og the Writer, Og the Agent, and Og the Publisher came to naught when they discovered, too late, that no one had yet learned to read, resulting in a potential audience of just Og himself. The only one of Og's multiple personalities able to smile at this fiasco was Og the King of Book Remainders. Those eleven books-on-boards were resold as kindling.

Bowed but not broken in spirit, the indomitable Og dreamed of publishing his novel in a format that his contemporaries could enjoy: a talking book! After much thought, much theorizing, and planning, Og constructed the world's first megaphone. He aimed the megaphone at a rock and read his novel at a shout, for it was his theory that in this manner he would imprint his voice--and his novel--in stone for eternity.

Upon recovering from the world's longest and most painful case of laryngitis to that time, Og realized that cave-dweller culture lacked the sophisticated technology necessary to recover his voice from the rock. His talking book contained his story, he knew, but it would not speak. By its silence, it mocked him. This, at last, broke the spirit of Og. Kicking the rock, he also broke all his toes, and on more than one occasion.

In cave-dweller society, the rock became known as Og's Folly. Og himself became known as Stupid Og or simply Stupid, or Mr. Big Shot Author, though the less well-bred citizenry called him Mr. Dumb Ass Troglodyte.

Humiliated, scorned, Og died a destitute laughingstock, which is by far the worst kind of laughingstock that one can be. His last request was that his body be consigned to a tar pit immediately on his death, for he believed that immersion in tar would preserve him until, thousands of years hence, technology had evolved that could restore a tar-preserved cadaver to a full, healthy life. The cave-dweller society had become more coarse over the years, and instead of honoring Og's request, they buried him in front of his rock, so that his neighbors, when they passed it every day, could laugh and point and say, "There lies Mr. Dumb Ass Troglodyte in the shadow of his stupid nontalking book-rock thing."

Millennia later, scientists and engineers at last produced the technology capable of recovering Og's shrill voice from the rock. The novel, which Og had titled My Loincloth is a Wildcat's Pelt, was published under the less sensational title Prehistoric Passion. The New York Times Book Review bemoaned the novelist's sexism, his militarism, and his "insensitivity to the rights of saber-toothed tigers and other predators who have suffered at the hand of man." Entertainment Weekly quipped that the time-travel element of the plot was "as poorly put together as a five-dollar watch" (though no one else noticed a time-travel element), and mocked Og's simple name by demanding, "Who does he think he is, anyway--Cher?"

The audio edition of the novel was read by Soupy Sales, who used a voice like that of Scooby Doo for all scenes from animal points of view, and a resonant imitation of Fred Flintstone for the viewpoint of the warrior character who narrates most of the tale. For archival purposes, a 21-hour reading of the entire text was recorded, but the only version marketed to the public was a two-hour abridgement; in a banner on the package, the publisher proudly proclaimed this condensed version to be "A Fast, Easy-Listening, Incomprehensible Treat!"

Good Og, rest in peace if you can.
( The Resident Loon Not a demographic. Do not measure., Sat 17 May 2008, 13:04, closed)

Some of the classics are good
but others are piss poor it's true. Pride and Prejudice was just chick lit before its time

GET ON WITH IT AND FUCK DARCY AND STOP WHINING
( Madam Marlboro wonders if you've found her yet, Sat 17 May 2008, 14:39, closed)

For...
"War
Huh, what is it good for? Books."

You get a click.

I too am a bit of a fan of Clancy and of course Hitchhikers Guide. "In Harms Way" was recently paraphrased by none other than Frankspencer.
(Bicycle Repairman "you're also a bit of a wanker", Sat 17 May 2008, 19:56, closed)

I have read lots of Dean Koontz
but his recent efforts have lost the plot. They now seem to all include a religious element, whereas before they were just scary. For example, Intensity was good, but The Taking had a ridiculous ending which paralleled the biblical flood.
( K2k6 has a proper job these days, Sun 18 May 2008, 12:52, closed)

hmm
Hurrah for horror that's not Stephen King. I personally loved Richard Laymon's books - unsettling and slightly scary, but mostly they were just completely over-the top gruesome, and incredibly fun to read.

"You arguing that it is, actually, good tends just to highlight your media whoreishness: Dan Brown, Rowling, the bible etc"

I'd disagree here. I've enjoyed all the Harry Potter books. Yes, they have some obviously lifted elements, and yes, there are better-written books out there, but these stories captured my imagination enough that I was out at midnight with a bunch of friends on the release dates to buy the most recent two. That's a sign of good books, that they inspire that much enjoyment in their audience.

I'd agree with you that media attention can get a lot of people to read a bad book too - I read the DaVinci code and have been grateful ever since that I borrowed it instead of buying it. The story was tat and, whilst it had the potential to be mindlessly diverting, the quality of the writing was such that on numerous occasions I actually dropped out of my reader's trance and noticed how clumsy it was, which is a cardinal sin to my way of looking at things.
( Mockingbird Practitioner of SCIENCE, Tue 20 May 2008, 9:16, closed)