Prince of Nothing by R. Scott Bakker. The three books in the first series are The Darkness That Comes Before, The Warrior Prophet, and The Thousandfold Thought. One of the best fantasy series ever written; highly recommended if you like dark, original fantasy set in a richly-designed world. Very deep and philosophical; the author is a philosophy Ph.D. Plot involves the complicated story of a grand Crusade being hijacked by a mysterious warrior-logician with superhuman reasoning abilities. Kushiel's Legacy by Jacqueline Carey. Books include Kushiel's Dart, Kushiel's Chosen, Kushiel's Avatar, Kushiel's Scion, Kushiel's Justice, and Kushiel's Mercy. The first one isn't so good; most people report better results starting from Scion. Emotionally powerful; the sort of book that makes you more deeply human after reading it. You will laugh, you will cry, you will gain a new appreciation for the beauty of the human condition. Plot involves love, lust, sexuality, religion, and politics in a fantastic world close to a hybrid of classical and medieval times, but with more angels. Silmarillion by J.R.R. Tolkien. You can learn a lot about a person by asking whether they prefer Lord of the Rings or Silmarillion. Rings is Tolkien's action-adventure story; Silmarillion is a combination of his world's history textbook and Bible. No one has ever constructed a fictional world like this before, and probably no one ever will again; Tolkien weaves an entire mythological system that rivals and surpasses that of the Greeks and Hebrews. Plot involves the creation of the world, the origin of evil, and the struggle of the elves and gods against the forces of darkness. Discworld by Terry Pratchett is a set of...wow, there must be twenty five or so books by now. They're funny, they're quick to read, they're ultra-quotable, and they're more philosophically interesting than you think at the time. Plots are many, but are all set on the Disc (a flat world supported by four elephants on the back of a giant turtle) and often involve its incompetent wizards or ragtag city watchmen. About as witty as you're likely to get without bringing Oscar Wilde back from the grave. A Song of Ice and Fire by George R. R. Martin is probably the hottest new fantasy series since Tolkien. It's not all that original, and it's not all that exciting, but it's solid, detailed, gritty, and very very well written. Soon to be an HBO series, or so people say. Plot involves the intricate struggle of several great noble houses for dominance in a world where seasons can last for decades and dragons are a recent memory. The Baroque Trilogy by Neal Stephenson. Books are Quiksilver, The Confusion, and The System of the World. This is the sort of historical fiction that teaches you more than you ever thought you wanted to know about a period which ends up being much mroe exciting than you thought; it also features ninjas, witches, czars, and of course Sir Isaac Newton. Spectacularly well-written and centered around the role of science in society. Plot revolves around the formation of the Royal Society in England and the context of Isaac Newton's discovery of gravity, but quickly fans out from there to include practically anything happening during the late seventeenth and early eighteenth century. Illuminatus by Robert Anton Wilson and Robert Shea. Written by two polymath semi-genius Playboy columnists utterly off their head on drugs during the 60s and 70s, and boy does it show. Probably something in it to offend everyone, no matter how hard to offend they usually are. However, it's less of a traditional fiction book than a one-of-a-kind literary machine for opening minds and making them question everything they thought they knew. Cults have been founded around this book, and not without some reason; even if like most people (probably including the authors) you don't believe any of it, it still does zaps your brain in a very particular way. Plot involves a secret evil society's attempt to "immanentize the eschaton", and the heroes' quest to stop them through mystic understanding, libertarian values, plain old contrariness, and especially sex drugs and rock and roll. Island on the Sea of Time/Emberverse by S.M. Stirling. Two series, one beginning with Island on the Sea of Time and the other with Dies the Fire. Stirling does his homework. He knows everything about everything, and uses the knowledge to write an absolutely compelling and believable account of things so outlandish that writing soberly about them seems impossible. These books are real page-turners, too. The plot of Island involves the island of Nantucket and its 21st century population suddenly being transported to 1100 BC, and its inhabitants having to rebuild civilization mostly from scratch. The other plot in Dies the Fire follows the inhabitants of 21st century America after some sort of event prevents all technology from working and plunges the world back into the Middle Ages. This is some of the best alternate history ever written, in my opinion. The Years of Rice and Salt is Kim Stanley Robinson's account of how the world would have developed without Europe. Made up of a series of short stories taking place from the 1300s to the 20th century, it follows Arabia, China, and the other great powers that rise to fill the void. Like Stirling, Robinson is so mind-bogglingly intelligent that his worlds feel completely plausible; the great Muslim-Chinese conflict of the 1900s matches World War II in scope and drama. Striking the Balance by Harry Turtledove - speaking of alternate historians who have the talent to make the utterly absurd seem completely plausible. This series of four books plus some extra sequels tacked on near the end follows the World War II earth after a conquering alien race has landed right in the middle of it. All sides try to build alliances with the aliens (who find Earth a harder egg to crack than they'd expected) and build a new balance of power. Along the way, it portrays World War II with a detail that few books, even genuine historical novels, can match, and creates one of the most interesting and creative alien races in all science-fiction. Uplift by David Brin's (Sundiver, Startide Rising, The Uplift War, Brightness Reef, Infinity's Shore, Heaven's Reach) is a collection of novels written in a universe where all intelligent species have been genetically engineered into sentience ("uplifted") by other intelligent species in a chain that goes back longer than anyone can remember. Humans have caused quite a stir by seeming to have arisen without being intelligently designed; they cause even more of a stir when they discover clues about the legendary first species of them all. The real joy of these books are the neo-chimps and neo-dolphins: animals in the mid stages of being raised to intelligent life. It comes closer than any other book I've read to really getting inside the head of a non-human being, and in the context of these apes and dolphins discusses the theme of conflict between rational intellect and animal nature - something we humans, of course, aren't immune from. It's also just a really excellent set of stories. Good Omens by Terry Pratchett and Neal Gaiman, is finally some light comic relief on this list, a book you can probably finish in a few days and enjoy every second of it. Like most books by its two authors, it mixes wit with humor with social commentary with a light-hearted but well-studied view of the supernatural. The plot involves an angel and a demon who spend so much time among humans that they "go native". In the end, they have to team up (with the help of the Anti-Christ) to prevent the Forces of Good and Forces of Evil from destroying the world as collateral damage in a colossal Battle of Armaggedon. Harry Potter and the Methods of Rationality by Eliezer Yudkowsky is a work of Harry Potter fan fiction, but a common reaction on reading it is "I don't usually like Harry Potter fanfiction, but WOW". Meant to serve sort of as a textbook on cognitive biases and the philosophy of science, it's also hilariously funny and deeply moving. Bonus points for getting even a quarter of the easter eggs and throwaway references.