The 100 Greatest Books, according to PD.com

[Cain]

I would have seconded it, regardless.

Also, I will draw up a list later today, for reals.

[Remington]

The Zombie Survival Guide -Max Brooks
1984 -George Orwell

[Requia ☣]

Dune by Frank Herbert and Cyteen by CJ Cherryh are the best science fiction that I've read.

Just finished reading this.   Seconded, and then some.

[Cain]

List of top books

Machiavelli - The Prince
Nassim Nicholas Taleb - Fooled by Randomness/Black Swan
Robert Anton Wilson and Robert Shea - The Illuminatus! Trilogy
Terry Pratchett - Thief of Time
Neil Gaiman - American Gods
Douglas Adams - The Hitch Hiker's Guide to the Galaxy
Chuck Palahniuk - Fight Club
Robert Rankin - Apocalypse: The Musical
Neal Stephenson - Snow Crash
Anthony Burgess - A Clockwork Orange (uncut UK edition)
Joesph Heller - Catch 22
Voltaire - Candide
Jonathan Swift - A Modest Proposal
Hunter S. Thompson - Fear and Loathing in Las Vegas
Albert Camus - The Rebel
Friedrich Nietzsche - Beyond Good and Evil
Unruh and Wilson - The Art of Memetics
Stephen Colbert - I am America, and So Can You
Douglas Hofstader - Godel, Escher, Bach
James Gleick - Chaos
John le Carre - The Perfect Spy
The Tao Teh Ching
Sun Tzu - The Art of War
Deleuze and Guattari - Anti-Oedipus
Deleuze and Guattari - A Thousand Plateaus
Kierkegaard - The Seducer's Diary
Mark Dery - Culture Jamming: Hacking, Slashing and Sniping in the Empire of Signs
Joesph Matheny and others - The Incunabula and Ong's Hat Papers
Howard Campbell - Poker without Cards
Robert Greene - The 48 Laws of Power

[Requia ☣]

Starship Troopers - Robert Heinlein

Seconded

[Cramulus]

List of top books

Nassim Nicholas Taleb - Fooled by Randomness/Black Swan
Robert Anton Wilson and Robert Shea - The Illuminatus! Trilogy
Neil Gaiman - American Gods
Douglas Adams - The Hitch Hiker's Guide to the Galaxy
Chuck Palahniuk - Fight Club
Hunter S. Thompson - Fear and Loathing in Las Vegas
Unruh and Wilson - The Art of Memetics
The Tao Teh Ching
Mark Dery - Culture Jamming: Hacking, Slashing and Sniping in the Empire of Signs
Robert Greene - The 48 Laws of Power

hell yeah seconded

[Arafelis]

The Bible (I could probably make a more focused list by book, but it's all pretty inter-related.)
Babylonian Talmud
Zhuangzi (probably inspired a lot of the PD, yet is much less well-known than the Tao Te Ching)
Bhagavad Gita
Science And Health With Key to the Scriptures - Mary Baker Eddy (One of the best philosophical texts I've ever read.  Also batshit crazy.)
(There were some Buddhist texts on change and substance that I thought were pretty inspired, but I'm having trouble remembering their names.)
(I can't put the Koran on the list because I've never read more than excerpts, but I think it probably deserves to be)
The Epic of Gilgamesh
Demian - Herman Hesse
Book of Five Rings - Musashi
One Hundred Years of Solitude - Gabriel Marquez
Don Quixote - Cervantes
Journals of Ayn Rand - (excerpts by Leonard Piekoff, edited by David Harriman)

I support the recommendations for Snow Crash, The Art of War, Hitchiker's Guide (all), The Prince, Breakfast of Champions, and something by PKD -- just not sure what yet. 

I'm not going to nominate House of Leaves by Danielewski, but I'm mentioning it in case someone else thinks it belongs but hasn't thought of it yet.

Other things I think worthy of mention as texts, although not books:
Planescape: Torment by Black Isle Studios (not the novelization)
Fallout by Black Isle Studios
Wikipedia
(Various) by Jack Chick
The Clouds - Aristophenes

[Love]

I would like to see Daniel Quinn's Ishmael on the list, or perhaps better for Discordians would be The Story of B... http://thestoryofb.com/ is my coverage on the book. May I suggest The Story of B replace my space.

Thank you for your considerations.

Hail Discordia!

[Soylent Green]

Dune - Frank Herbert
Hitchhikers' Guide to the Galaxy - Douglas Adams
A Modest Proposal - Johnathan Swift
The Constitution Of the United States
Common Sense - Thomas Paine
The Martian Chronicles - Ray Bradbury
Thief of Time - Terry Pratchett
Goedel, Escher, Bach - Douglass Hofstadter
No Exit - Sarte
Catch 22 - Joseph Heller
On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life - Charles Darwin
The Illuminatus! Trilogy - R. A. Wilson
Snow Crash - Neal Stephenson
Cryptonomicon - Neal Stephenson
American Gods - Neil Gaiman
Neuromancer - W. Gibson
Fooled by Randomness - N. N. Taleb
To Kill A Mockingbird - Harper Lee
Breakfast Of Champions - Kurt Vonnegut
Slaughterhouse 5 - Kurt Vonnegut
Do Androids Dream of Electric Sheep - Phillip K Dick
Fight Club - Chuck Palahniuk
Watchmen - Alan Moore
The Prince - Nicolo Machiavelli
1984 -George Orwell
Cyteen - CJ Cherryh
Fooled by Randomness/Black Swan - Nassim Nicholas Taleb
Surely you're joking Mr. Feynmann - Richard Feynman
Steal This Book - Abbie Hoffman
Starship Troopers - Robert A Heinlein
Fear and Loathing in Las Vegas - Hunter S. Thompson
The Art of Memetics - Unruh and Wilson
The Tao Teh Ching - Lao Tsu
Culture Jamming: Hacking, Slashing and Sniping in the Empire of Signs - Mark Dery

You had a few repeats, fixed.

Also, I propose:
The Communist Manifesto - Karl Marx
Atlas Shrugged - Ayn Rand (even though everyone here hates it lol)
Don Quixote - Cervantes
Beowulf
Thus Spoke Zarathustra - Nietzsche
Alice in Wonderland and Through the Looking Glass - Carroll

[Requia ☣]

Promethea - Alan Moore
Atlas Shrugged - Ayn Rand (I'm sure people will knock it off soon, but its on for now).

seconding these, went back through and added some I missed

we have 42/100 so far, apparently PD is picky.

[Rumckle]

The Raw Shark Texts- Steven Hall
If just for the cool pictures and the fact it turns into a flipbook part way through

[tpc: Zelath]

Illusions - the advenntures of a reluctant messiah by Richard Bach..
Borrughs nova express trilogy
Carlos Castaneda

[Soylent Green]

A Clockwork Orange - anthony burgess

Flatland - Edward A. Abbott

The Quran - Mohammad

Alice In Wonderland and Through the Looking Glass - Lewis Carroll

Candide - Voltaire

The Republic - Plato

The Communist Manifesto - Karl Marx

Catcher in the Rye - J.D. Salinger

Fahrenheit 451 - I forget.

Lord of the Rings - J.R.R. Tolkien

Lord of the Flies - william golding

Chronicles of Narnia - C.S Lewis

Brave New World - Aldous Huxley

Beowulf

Connecticut Yankee in King Arthur's Court - Mark Twain

Don Quxiote - Cervantes

[Pope Pixie Pickle]

Seconding or thirding..

Thief Of Time- Terry Pratchett

Tao Te Ching - Lao Tzu

Art of War- Sun Tzu

Catch 22- Joseph Heller

James Gleick - Chaos

American Gods- Neil Gaiman

The Watchmen- Alan Moore

Fear And Loathing In Las Vegas- Hunter S Thomspon

neverwhere- Neil Gaiman

The Zombie Survival Guide -Max Brooks

Adding to the list

Anansi Boys- neil Gaiman

Sandman- Neil Gaiman (ok im definately a HUUUGE fan)

Hells Angels- Hunter S Thompson

Fear and Loathing on the Campaign Trail- HST

Hellblazer (vertigo comic series, various writers)

Zen and The Art Of Motorcycle Maintainance.

Condensed Chaos- Phil Hine

Farenheit 451 seconded also...

and finally for at least today- Stranger in a Strange land by Robert Heinlein

[Rumckle]

I didn't think Anansi Boys was as good as American Gods or Neverwhere (Plus I have a thing against having too many of the same author in the one list)