Tyler Cowen linked to Alex Carnevale’s top 100 SF&F works, which has some odd choices (Jack Vance and Ursula K. LeGuin appear to have been the compiler’s favourite authors). In the comments to Tyler’s post, an alternate (unannotated) list by David Pringle was recommended. Pringle’s list doesn’t include Fantasy books, so there’s less overlap between the two than you might expect.

No list of this kind is, or can be, truly authoritative, but there are some common items on each list I can’t criticize as being in the top of the field:

• The Moon is a Harsh Mistress, Robert Heinlein. Carnevale has this at #2. Pringle doesn’t list it, but has several other (in my opinion, lesser) Heinlein works on his list. This is one of the best libertarian SF novels ever. Even if you’re not over-fond of his work, this short novel is well worth reading.
• Frankenstein Mary Shelley. This book made #6 for Carnevale, but didn’t make Pringle’s list. I read this when I was 12, and it made quite an impression on me, although I have to admit I like it much more now than I did on first reading it.
• Dune, Frank Herbert. Carnevale likes it much more than Pringle (#11 versus #48). I liked the original book, but lost interest sometime later in the series.
• The Hobbit and The Lord of the Rings, J.R.R. Tolkien. Not the original fantasy work, but probably the most common source for inspiration (and verging-on-outright-plagiarism) for an entire sub-field of Fantasy.
• Stranger in a Strange Land, Robert Heinlein. One of the most subversive books ever published, at least as far as the middle class of the 1960’s was concerned. On the surface, it’s the story of a Martian named Smith. It seems to be one of those books you either love or hate — not much middle ground here.
• Alice in Wonderland, Lewis Carroll. Pair this with Carroll’s Through the Looking-Glass for the full effect. Another author whose work has been strip-mined for ideas by later writers.
• 1984 by George Orwell. Pringle’s #1 pick and Carnevale’s #26. I’d certainly put it in my top ten.
• Fahrenheit 451, Ray Bradbury. This book made both lists (#8 for Pringle,#27 for Carnevale), but I’m afraid I’ve never read it (I tried a couple of Bradbury books when I was in my early teens, but never warmed to him as an author).
• The Man in the High Castle, Philip K. Dick. Another book that made both lists, but which I haven’t read, and for similar reasons. Early experiences with an author’s work can have long-lasting effects.
• A Fire upon the Deep by Vernor Vinge. A book that appeals to both fans of the huge stage of deep space and aficionados of the early Internet.
• Citizen of the Galaxy, Robert Heinlein. One of the very best “young adult” SF novels from before they called them that. Both a coming of age novel and a condemnation of slavery and hypocrisy. Powerful stuff for young minds.
• Starship Troopers, Robert Heinlein. Another great polarizer: it’s either the best military SF novel ever written or the worst piece of hyper-Fascist propaganda ever written. It’s interesting that Heinlein wrote this book at about the same time as he was working on Stranger. Readers who only knew about the one work might have suffered severe mental whiplash to find he’d written the other one, too. Either way, pretend that the film never happened (aside from the names, it doesn’t have much to do with the novel).
• The Hitchhiker’s Guide to the Galaxy, Douglas Adams. You want whimsical? HHG took whimsy to a whole different level. What Terry Pratchett did with Fantasy, Adams did with SF.
• Animal Farm, George Orwell. A book that suffers from being pushed on high school students as mandatory reading. The revolution on the farm, and the aftermath.
• The Baroque Cycle, Neal Stephenson. A huge four-volume work that repays the effort to work through. Some authors work best at a certain length (short story, novella, novel, etc.). Stephenson seems to work best at the library-shelf level.
• Ringworld, Larry Niven. I wouldn’t call this a top-ten, but the series of books in this series certainly belong in the top 100.
• A Canticle for Leibowitz, Walter M. Miller. Post-apocalyptic done well.
• Snow Crash, Neal Stephenson. Certainly one of the most entertaining books I’ve ever read (it helped that I was working in the computer industry at the time). From Stephenson’s earlier less-than-library-shelf-length period.
• The Day of the Triffids, John Wyndham. A book I had to read in middle school, yet one I still recall with great affection. Few books can survive being forced down kids’ throats. This one can.
• Memory, Mirror Dance, and A Civil Campaign, Lois McMaster Bujold. I had trouble stopping at just three of Bujold’s “Vorkosigan” series, as they’re all highly entertaining and deeply engaging. Some call it space opera, but it’s far more involved and well-executed than that easy label would indicate. One of the very best SF authors ever. Her more recent work is predominantly Fantasy, and while they’re very good, I’m more interested in her SF writing.
• The Atrocity Archive and The Jennifer Morgue, Charles Stross. Imagine if the British secret service had an even more eldritch secret service component. But run strictly according to civil service rules.
• Pyramids, Men at Arms, Interesting Times, and The Wee Free Men, Terry Pratchett. Another author for whom it is difficult to select even a few examples (they’re all so good). His Discworld series started as a simple pastiche of typical swords-and-sorcery novels, but which quickly outgrew the confines of the first few books. The Wee Free Men is the first of a series of Young Adult novels for the Discworld (including A Hat Full of Sky, Wintersmith and the forthcoming I Shall Wear Midnight).
• Old Man’s War, John Scalzi. Another military SF story, but so well thought-out and executed as to transcend the ordinary levels of the sub-genre. Follow-on works are equally good (The Ghost Brigades, The Last Colony, and Zoe’s Tale).
• Island in the Sea of Time, S.M. Stirling. Another time-travel story, but avoiding the usual pitfalls of time travel story lines (the secret was to go back before written history…). This was the first book of a trilogy. Stirling is currently completing a related series of stories hinging on what happened to the world left behind in the original trilogy (starting with Dies the Fire).
• The Probability Broach, L. Neil Smith. More interesting (and amusing) ideas per page than any other novel of its era. Another libertarian book, but don’t let the label scare you off: great reading.

What’s that? No Clarke? No Asimov? No Sturgeon? No Card? No Zelazny? No Brunner? Not in the top whatever-number-I-stopped-at. Each has strong fans, and some good work, but not top-rank in my view.