This one is a few months old, but NPR published their list of Top 100 Science-Fiction, Fantasy Books (as nominated/voted by their readers). I've got nothing better to do right now, so let me go over the list. I'll be boldfacing the ones I read, and adding comments as applicable.
- The Lord Of The Rings Trilogy, by J.R.R. Tolkien
multiple times, along with multiple readings of The Hobbit and one reading of The Silmarillion. The last read too much like a history book, and not in a good way. Oh, and I never had any interest in reading the various notes and incomplete other tales published posthumously by JRRT's son.
- The Hitchhiker’s Guide To The Galaxy, by Douglas Adams
I also read this series multiple times; I recall buying a British copy of Life, the Universe, and Everything before it was released in the USA. (The original release did not include the "Belgium" joke.) I re-read the whole series recently (except Salmon of a Doubt; still haven't gotten to that one) before reading And Another Thing… (the alleged sixth Hitchhiker's Guide book writted by Eoin Colfer). The quality of the series plummets by the end, as Adams clearly didn't want to write Hitchhiker books anymore; and Colfer failed to capture the spirit of the series (and he tried way too hard to do so, by filling the book with references to characters and events from previous books – rather than being sufficiently creative in generating new ones – in order to cement his book hamhanded into the series).
- Ender’s Game, by Orson Scott Card
I read this book many times, before tentatively dipping my toe into any of the following books. I've only read four of them, total (the ones following Ender himself, not the side series following his brother or the other kid).
- The Dune Chronicles, by Frank Herbert
I read at least six of them before stopping, which was at least three more than I should have read. The first one's very good, if wordy; but each subsequent book spends more and more space being wordy before wrapping things up as quickly as possible at the very end. The fourth, God Emperor of Dune, was the worst of the ones I read, IMO.
- A Song Of Ice And Fire Series, by George R. R. Martin
- 1984, by George Orwell
Of course, I was in high school in the year 1984, so that simple fact meant that Orwell's book was going to be on every assigned reading list in the country. I did read it more than once, but I never got around to reading his next most famous book, Animal Farm. (I've seen multiple adaptations of it, though.)
- Fahrenheit 451, by Ray Bradbury
Read this one way back in the 70s. Read a lot of Bradbury back then (The Martian Chronicles, etc.); but it's been so long that my memories of them are a bit fuzzy.
- The Foundation Trilogy, by Isaac Asimov
The original trilogy is great. The next few books where Asimov tried to tie his Foundation series, Robot series, and other works into a single consistent universe? Not as much. And I gave up on the prequel novels written by other authors after Asimov's demise.
- Brave New World, by Aldous Huxley
Read this one around the same time as 1984. In 1984.
- American Gods, by Neil Gaiman
Definitely a good one, as is the sequel Anansi Boys.
- The Princess Bride, by William Goldman
I've seen the movie (and if you haven't, you're dead to me) countless times, but never read the book.
- The Wheel Of Time Series, by Robert Jordan
- Animal Farm by George Orwell
See 1984, above.
- Neuromancer, by William Gibson
I started reading it; but by the time I'd picked it up it was decades old and out of date, and I'd already seen the concepts in it used elsewhere to point of becoming clichés. Made it hard to get into. I may try again some other time.
- Watchmen, by Alan Moore
Far better than the movie; but I still enjoyed the movie, too.
- I, Robot, by Isaac Asimov
Multiple times. (I read a lot of Asimov's books over and over when I was younger, and in a small town – North Smithfield, RI – which didn't have a particularly large science fiction section in their library.) Rather than just use this one title, they should have made the entire series this entry on the list.
- Stranger In A Strange Land, by Robert Heinlein
Multiple times, though not recently; and read the full and uncut version when that came out. I also read all of the Heinlein books (mostly his juvenile ones) a lot when I was younger, and wondered what the hell happened to him once I hit his later books.
- The Kingkiller Chronicles, by Patrick Rothfuss
I confess to never having heard of this one.
- Slaughterhouse-Five, by Kurt Vonnegut
- Frankenstein, by Mary Shelley
- Do Androids Dream Of Electric Sheep?, by Philip K. Dick
I read a lot of Phillip K. Dick a few years back; I can't remember if this is one I read for the first time then, or one I'd already read previously.
- The Handmaid’s Tale, by Margaret Atwood
- The Dark Tower Series, by Stephen King
I read the first three of four, then lost interest. In fact, I haven't read anything by King in years.
- 2001: A Space Odyssey, by Arthur C. Clarke
And the sequels.
- The Stand, by Stephen King
Possibly my favorite King novel, in the original and the expanded version.
- Snow Crash, by Neal Stephenson
My favorite Stephenson novel. I've only read three or four others; he seems hit-or-miss to me.
- The Martian Chronicles, by Ray Bradbury
- Cat’s Cradle, by Kurt Vonnegut
- The Sandman Series, by Neil Gaiman
- A Clockwork Orange, by Anthony Burgess
Including the final chapter that wasn't in the original US publication (or the movie).
- Starship Troopers, by Robert Heinlein
And the movie was a travesty.
- Watership Down, by Richard Adams
Just the cartoon.
- Dragonflight, by Anne McCaffrey
Read at least six of these before stopping.
- The Moon Is A Harsh Mistress, by Robert Heinlein
Possibly my favorite Heinlein.
- A Canticle For Leibowitz, by Walter M. Miller
- The Time Machine, by H.G. Wells
- 20,000 Leagues Under The Sea, by Jules Verne
Read all my H.G. Wells, but never got around to Verne for some reason.
- Flowers For Algernon, by Daniel Keys
- The War Of The Worlds, by H.G. Wells
- The Chronicles Of Amber, by Roger Zelazny
- The Belgariad, by David Eddings
- The Mists Of Avalon, by Marion Zimmer Bradley
- The Mistborn Series, by Brandon Sanderson
- Ringworld, by Larry Niven
And the sequels. I like Niven's Known Space novels, even if they are a bit uneven; but I think Niven's best work is in his collaborations – especially with Jerry Pournelle. Footfall is one of my favorite alien invasion novels, and there's another sequel to The Mote in God's Eye coming soon.
- The Left Hand Of Darkness, by Ursula K. LeGuin
- The Silmarillion, by J.R.R. Tolkien
See my comments for The Lord of the Rings above, and there's no reason why (in a list limited to one hundred entries) this should be listed as a separate item rather than rolled in with the above work.
- The Once And Future King, by T.H. White
- Neverwhere, by Neil Gaiman
- Childhood’s End, by Arthur C. Clarke
- Contact, by Carl Sagan
And I join Mr. Garrison (teacher, South Park Elementary) in condemning the movie adaptation.
- The Hyperion Cantos, by Dan Simmons
- Stardust, by Neil Gaiman
- Cryptonomicon, by Neal Stephenson
Another one by Stephenson that I liked.
- World War Z, by Max Brooks
Not yet, but it's on my Kindle.
- The Last Unicorn, by Peter S. Beagle
- The Forever War, by Joe Haldeman
- Small Gods, by Terry Pratchett
Haven't gotten to this one yet. In the past, I've read a dozen or so of the Discworld books, not necessarily in a consistent order; this year, I've started again reading (or re-reading) them all. I'm up to the eighth, Guards, Guards! (I also own a few of the video adaptations.) The entire Discworld series needs to (1) be contained on this list as a single entry, and (2) by much higher up on the list. There's no reason to be inconsistent by listing some series as a single unit and breaking others up into separate books to take up multiple slots of the list – which leaves less room for the many other authors who didn't make it onto the list at all.
- The Chronicles Of Thomas Covenant, The Unbeliever, by Stephen R. Donaldson
The first and second trilogies, back when they came out, and but the first book of the third trilogy.
- The Vorkosigan Saga, by Lois McMaster Bujold
One or two of them.
- Going Postal, by Terry Pratchett
Another of the Discworld books which I haven't read yet, to the best of my recollection. See note above at Small Gods.
- The Mote In God’s Eye, by Larry Niven & Jerry Pournelle
And the first sequel, and there's another coming.
- The Sword Of Truth, by Terry Goodkind
- The Road, by Cormac McCarthy
- Jonathan Strange & Mr Norrell, by Susanna Clarke
- I Am Legend, by Richard Matheson
- The Riftwar Saga, by Raymond E. Feist
- The Shannara Trilogy, by Terry Brooks
- The Conan The Barbarian Series, by R.E. Howard
I read at least one Conan book, but it didn't grab me, by Crom.
- The Farseer Trilogy, by Robin Hobb
- The Time Traveler’s Wife, by Audrey Niffenegger
- The Way Of Kings, by Brandon Sanderson
- A Journey To The Center Of The Earth, by Jules Verne
- The Legend Of Drizzt Series, by R.A. Salvatore
- Old Man’s War, by John Scalzi
- The Diamond Age, by Neil Stephenson
Read this one, but not the rest of the Baroque Cycle.
- Rendezvous With Rama, by Arthur C. Clarke
A couple of times, but not the sequels.
- The Kushiel’s Legacy Series, by Jacqueline Carey
- The Dispossessed, by Ursula K. LeGuin
- Something Wicked This Way Comes, by Ray Bradbury
- Wicked, by Gregory Maguire
Haven't seen the stage adaptation, though, but it seems to have changed a number of things.
- The Malazan Book Of The Fallen Series, by Steven Erikson
- The Eyre Affair, by Jasper Fforde
And two or three of the sequels.
- The Culture Series, by Iain M. Banks
- The Crystal Cave, by Mary Stewart
- Anathem, by Neal Stephenson
- The Codex Alera Series, by Jim Butcher
- The Book Of The New Sun, by Gene Wolfe
- The Thrawn Trilogy, by Timothy Zahn
- The Outlander Series, by Diana Gabaldan
- The Elric Saga, by Michael Moorcock
- The Illustrated Man, by Ray Bradbury
- Sunshine, by Robin McKinley
- A Fire Upon The Deep, by Vernor Vinge
- The Caves Of Steel, by Isaac Asimov
Part of Asimov's Robot series, all of which should have been on the list as a single entry.
- The Mars Trilogy, by Kim Stanley Robinson
- Lucifer’s Hammer, by Larry Niven & Jerry Pournelle
I repeat my opinion that some of Niven's best work was in his collaborations; the same goes for Pournelle. Their styles and strengths blended and complemented each other quite well.
- Doomsday Book, by Connie Willis
- Perdido Street Station, by China Mieville
- The Xanth Series, by Piers Anthony
I read the first eight or so, back when there were only eight or so, and tired of them quickly. Piers Anthony's series generally start out strong, but overstay their welcome. (How many Xanth books are there now? 20? 30?) The Incarnations of Immortality series was better, and shorter; and the one might help explain the other. (Of course it was supposed to be five volumes, then got padded to seven, and I never read the recent eighth.)
- The Space Trilogy, by C.S. Lewis
Just the Narnia books.