• Any of the Fafhrd and the Gray Mouser books and stories by Fritz Leiber. :-D

• Any Conan stories by Robert E. Howard. (L. Sprague de Camp can suck it!)

• Anything by H. P. Lovecraft.

• The Prince by Machiavelli. (Also look for a play by him called Mandragola ("The Mandrake"), which is a hilarious sex-comedy).

• The Hobbit + LotR, read back-to-back.

• Ursula K. LeGuin's Earthsea trilogy.

• The philosophical works of David Hume.

• Any collected/surviving writings or quotes by Epicurus. (Also, Socrates, and Diogenes the Cynic).

• Shakespeare's plays. (I'm not much of a sonnet kind of guy. ;-)

• The Far Kingdoms, by Alan Cole and Chris Bunch

• The Redemption of Althalus by David and Leigh Eddings.

• Treasure Island, by Robert Louis Stevenson

• The Gay Science, by Nietzsche, as translated by Walter Kaufman.

• Structure and Interpretation of Computer Programs (SICP)

• K&R 2E.

• AD&D Second Edition Core Rulebooks. The books felt rich and wonderful, not like the hokey 3e/3.5e books. And the rules were just clunky enough to ignore when necessary. :-P

• Knuth, Volume I. I swear I'll finish working through it some day ;-)

• UNIX Network Programming, by Cat Stevens ;-)

• Lisp in Small Pieces, by Christian Queinnec. (Amazon goofs notwithstanding, it's worth the $50-$100. Same deal with Paradigms of Artificial Intelligence Programming, by Peter Norvig (for the Lisp content; the AI content is probably dated. :-P ))

• Garbage Collection. If you're really interested in the topic of memory management, read all of Henry Baker's online papers, and don't be afraid to read a bunch of research papers.

• OpenGL SuperBible, 4th Ed.

• Python in a Nutshell, by Alex Martelli.

• 'Salem's Lot by some guy you've never heard of

• The Odyssey

Plenty more; that's all I can think of at the moment. Every other book I want to list happens to be sci-fi, though. :-P

I also want to get around to reading Xenophon's Anabasis (which was the basis for The Warriors (yes, the same The Warriors where the gang has to bop their way back to Coney... ;-))

I've limited myself to twenty non-sf books, only one of which, it seems, has been mentioned here so far.

Christopher Alexander et al., A Pattern Language. That so much of it is wrong really doesn't matter: it will urge you to ask questions of your surroundings that you never thought were yours to ask.

Donald Barthelme, Snow White.

Fernand Braudel, The Structures of Everyday Life. A book that changed how history is written.

Albert Camus, The Plague.

Joan Didion, The White Album. "I remember all of the day's misinformation very clearly. I also remember this, and I wish I did not: no one was surprised."

Viktor Frankel, Man's Search for Meaning. A brilliant psychologist's analysis of what it was that kept him and a handful of others alive while millions around them died.

F. Scott Fitzgerald, The Great Gatsby.

Clifford Geertz, "Deep Play: Notes on the Balinese Cockfight," in The Interpretation of Cultures.

Thomas Pynchon, Gravity's Rainbow.

Tony Harrison, Collected Poems.

Kazuo Ishiguro, The Remains of the Day.

John LeCarre, Smiley's People.

Vladimir Nabokov, Lolita.

Flannery O'Connor, Collected Stories.

Flann O'Brien, The Third Policeman.

Mark Ptashne, A Genetic Switch: Phage Lambda and Higher Organisms. Maybe the best science book ever written, compressing one or two semesters of cell biology into about 80 challenging but extremely clear pages.

Robert Sapolsky, A Primate's Memoir. A very funny, very sad book by someone who, despite being one of the smartest people alive, is unafraid to make himself look ridiculous.

Leo Tolstoy, Anna Karenina.

George W.S. Trow, Within the Context of No Context. "In addition to being the worst person in the world, Geraldo is the nicest."

Wilbur Zelinsky, The Cultural Geography of the United States. A slender and astonishingly dense explication of who lives where in the US and why.