Since 'What's your favourite' topics are MY favourite ones, I'd create another one:
What are your favourite books, what did you enjoy reading, or what book was an unique experience for you?
My favourite books of all times(like all all) are Sherlock Holmes books from Sir Arthur Conan Doyle - for flawless logic and intelligence and Terry Pratchett's Discworld series (simple love those... And I don't even know why)
Another books I like or love (well.. In fact, something in between :D ) are:
Hitchhiker's guide to the galaxy (particulary first one, which I've red several times... Second one was good as well, not so great though)
Last Chance to See - I reccommend this one to every single person that liked Hitchhiker. Absolutely different topic of the whole book, but humor is still excellent.
Agatha Christie and her work (And Then There Were None is one of the best books I've ever red... I miss perfect logic that was in Sherlock Holmes in most of her books, though. It kinda seems to me.. Unreal. Or just lucky.)
The Lord of the rings (of course :D )
Sapkowski's Witcher - any book
Sergey Lukyanenko - Night Watch and sequels
I've even enjoyed Harry Potter, cause it was pretty read-able
I'm sure there's much more books I've enjoyed, but those come in mind, therefore I've enjoyed them most I guess :D

I love Dune and Michael Crichton
also, of the lord of the ring series, I really only enjoyed the hobbit, the others were alright, but the hobbit was fantastic to me..

-Discworld Series
-Planescape Blood Wars Trilogy
-BattleTech Books (old ones)
-Philip K. Dick
-Marion Zimmer, The Supreme Power Quadrilogy

Dune. Didn't have the chance to read the new ones yet.
Darkover series by Marion Zimmer Bradley - superior to all of her fantasy books.
A book with some nice sci-fi short stories, can't remember which one though. All of them made me laugh/wonder/shiver..

In my opinion, you aren't missing much. I read the first of the new ones (House Harkonnen?) and was totally put off reading any of the others.
The original Dune series was good, particularly the first one. Philip K. Dick's stuff is good (having so far read "Do Androids Dream of Electric Sheep" and "Ubik"). I also enjoyed William Gibson's "Neuromancer."
Can't go wrong with anything by Terry Pratchett. Including "Where's My Cow?" :)

Same. Although I am rather odd and I prefer God Emperor of Dune over all the others..

Well, I like reading in general, but of late, all I mainly read is for school.
I just finished Integrative Approaches to Psychology and Christianity
I am also rereading The Hobbit, and will then reread The Lord of the Rings. I have read these maybe 4 to 6 times already, but I have read them off and on since I was in High School way back when.
I like Science Fiction, Fantasy, or books by Tony Hillerman as well.

i'm a black library fan horus heresy strikes again

Anything by Harlan Ellison, Terry Pratchet, and Douglas Adams(except for the The Salmon of Doubt I haven't read it yet).
One of my favorite works of philosophy is Thus Spake Zarathustra by Friedrich Nietzsche.
I liked the Frank Herbert version of the Dune chronicles. I won't touch any of the new ones for obvious reasons.
The Stand (uncut) by Stephen King is another favorite. The mini-series by the same name wasn't bad either. They really did a good job with their choice of the actor who played Flagg; he looked very much like what I imagined he looked like in the book.
The Cyberiad by Stanislaw Lem. Awesome collection of short stories that has some of the most amazing writing to be ever put down on paper. I like a lot of his books but that is my favorite by him.

John M. Ford's How Much For Just The Planet.
It is a Star Trek book, but don't hold that against it. Kirk, Klingons, musicals (the pirate queen's song is good, but there are others), golf (Scotty playing his Klingon counterpart for the honour of the Enterprise! Oh, and the course is in a minefield...), inflatable decoy starships, milkshake, romantic comedy, hijinks, and a brilliant ending. Even if you don't like Star Trek - and I don't, really, I don't find it to be interesting as science fiction or in itself - you'll probably enjoy it.
Amazon has an excerpt from the Chapter One, before the real weirdness begins. I'm tempted to copy and paste bits here, but I'd have a hard time deciding which. Go read it. It's fun.

Random side comment @Throdax, I was on the forum listing site and on the most recent things on the wishlist it had you requesting starcontrol 2. SC2 is free for download as Ur-Quan Masters. http://sc2.sourceforge.net/
Onto books again... most of the things mentioned on here I've read already or been meaning to. I'm a big fan of the Hobbit, more than I am of LOTR, though LOTR isn't bad either. When I was younger I used to read a lot more and went through a lot of fantasy and sci fi. I like/have read Modesitt, discworld, used to love dragonlance as a early teenager (but its a little too juvenile now for me), original dune was good, hitchhiker's guide, wheel of time (WAY TOO LONG), the reality dysfunction series (good, but ending was a cop-out), the Death Gate Cycle (still one of my faves), Ender's Game (also one of my faves). Also, whatever that series is called with Pug who becomes like the all powerful magician, that ones pretty good as well. I've also read waaay too many sci-fi novels and short stories to remember them all.
Oh and Ursula Le Guin is awesome. I especially like the Earthsea (? maybe forgetting exact title) novels, but I haven't read them in a long time.

For me, it makes more sense to list authors or series, rather than individual books. So here, in no particular order:
Isaac Asimov
Frank Herbert
Robert Heinlein
Douglas Adams
Terry Pratchett
Night's Dawn trilogy (The Reality Dysfunction) (And yes, I agree the ending was lame, but the rest was awesome!)
Neil Gaiman
Eric Flint
And a few individual titles:
Ayn Rand - The Fountainhead
Tom Robbins - Fierce Invalids Home From Hot Climates
Robert Shea / Robert Anton Wilson - The Illuminatus! trilogy
And finally, anything at all by Larry Niven. He is my all time favourite author.

A look at my Bedside stack:
The Lord of Light
The Great Book of Amber
Ender's Game
Blood Meridian
BTW: I think Roger Zelazny should get more love!

I'm such a fool..
House of Leaves.

The Wheel of Time is possibly my favourite in-depth series. The authoring world suffered a real blow when Robert Jordan passed away.
I'm wanting to start reading Brandon Sanderson as he is writing WoT book 12.
Raymond E Feist has also been raised to my Best Author Ever list.
David Eddings - Belgariad, Mallorean, Elenium and Tamuli. The Dreamers didn't do it for me. And I wish there were more books in the Redemption of Althalus mythos.
Simon R Green - Deatherstalker, Hawk and Fisher/Blue Moon, Nightside and Secret Histories. And his stand alone books. Also one of my favourite authors ever.
I enjoy RA Salvatore, Michael Stackpole, Christopher Stasheff, Terry Pratchett, Terry Goodkind, Tad Williams (at times), Piers Anthony (at times) and quite a few others.
Clive Cussler (Dirk Pitt series) are about the only non-fantasy that I read.
I've also enjoyed the books Sorcerer's Son and The Crystal Palace though I have never found the third book. Same with The Halfblood Chronicles - Enjoyed 1-3 but I don't think 4 was ever written as Andre Norton passed away.
The moral of the above is to read Simon R Green :)
Karl