The following are summaries of the top ten books, but you can visit the article through the link above (or at the end of the list) to take a deeper look at the other fifteen.
1) To Your Scattered Bodies Go by Philip José Farmer SF FARMER (we also have the movie under DVD RIVERWOR)
(We have this work, along with the second book, The Fabulous Riverboat, under the title: Riverworld)
The first book in the Riverworld Saga begins with everyone who has ever lived on Earth suddenly finding themselves in a new world by a river. All their food is provided, but there is no clue as to the purpose of their new existence. Sir Richard Burton is the first to find the waystation, and Burton and a band made up of Alice Liddle Hargreaves, a Neanderthal, a Holocaust survivor, and an alien decide to travel the river to find out who brought this whole thing about and what their intentions are.
2) The Shadow of the Torturer by Gene Wolfe
(We have this work, along with the second book, The Claw of the Conciliator, under the title: Shadow & Claw)
The first book in the The Book of the New Sun series, this book follows Severian, who is an apprentice in the Guild of Torturers. Severian is soon exiled from the only home he has ever known, when he commits the ultimate sin of his guild by showing mercy to his victim. However, it seems that Severian has a bigger destiny than just that of a torturer.
3) Anathem by Neil Stephenson
SF STEPHENS and AD SF STEPHENS
Fraa Erasmas is a young "avout" living in the Concent of Saunt Edhar, (a monastary-like place) which protects the scholars of mathematics, science, and philosophy inside it from the outside "saecular" world and its influences (and technology). During the rite of Apert, fraas and suurs leave the grounds of the concent, and the concent opens its doors to visiting "extras." Neither side is quite prepared, though, for the threat that is coming, and both sides will have to work together, if they want to stop it. Erasmas soon finds himself a key player in the chaos that is coming.
4) Revelation Space by Alastair Reynolds
The first book in the Revelation Space series, scientist, Dan Sylveste, knows that the Amarantin civilization was destroyed just as it was on the verge of discovering space flight. Now, he needs to solve the "riddle" of the Amarantin, before it happens again, and he will need the help of the dangerous cyborg crew aboard the starship, Nostalgia for Infinity. There are forces at work that want to stop him, because there was a good reason for the destruction of the Amarantin.
5) The Left Hand of Darkness by Ursula K. Le Guin
One of the books in Le Guin's Hainish Cycle, The Left Hand of Darkness is considered, by many, to be a "groundbreaking" work of science fiction. Genly Ai, a human man, visits the alien winter world of Gethen as an emissary, where he hopes to discuss with the beings of the planet, the Gethians, their planet's being included in the growing intergalactic civilization. However, he must learn to understand the ways of the Gethens, however different they are, and have them understand his ways (and those of the civilization), in return.
6) I, Robot by Isaac Asimov
SF ASIMOV (we also have the movie under DVD I)
There are three laws of Robotics: 1) a robot may not cause harm to, or allow a human to come to harm 2) a robot must obey orders of humans (unless it violates the first law), 3) a robot must protect its existence (unless it violates the first or second law). I, Robot is a collection of stories that Asimov wrote about robots from the 1940s and 1950s.
7) The Sirens of Titan by Kurt Vonnegut
Malachi Constant is the richest and most depraved man on Earth, who takes part in several interplanetary wars, traveling from Earth to Mars to Mercury and to Titan. Constant finds out that all of the incidents within his travels came at the hands of Winston Niles Rumfoord. Kurt Vonnegut was a big inspiriation for Douglas Adam's The Hitchhiker's Guide to the Galaxy (I think you will see it too).
8) Contact by Carl Sagan
(we also have the movie under DVD CONTACT)
After years of scanning the galaxy for any signs of communication from other life forms, a team of scientists, including Eleanor Arroway (the person who discovered the first communication), belive they have found what they were looking for. However, this discovery brings up bigger, more dangerous questions of not just traveling out to meet these new lifeforms (using the plans for the "Machine" that they sent), but if they really should. Sagan also gives scientific explanations on how things work.
9) Red Mars by Kim Stanley Robinson
The first book in the Mars Trilogy, Robinson looks at the colonization of Mars in the year 2026. A group of one hundred colonists is sent to begin terrforming the red planet. Each member of the group seems to have a different reason for traveling to Mars, and each person's personality also leads to conflict amongst the group. There also apear to be some in the group that would prefer that no changes be made to the planet at all.
10) Pandora's Star by Peter F. Hamilton
This is the first book in the Commonwealth Saga. It is the year 2380, and the Intersolar Commonwealth is made up of more than 600 worlds, stretching 400 lightyears in diameter. The worlds are connected through transport "wormholes" (tunnel like transportation). An astronomer, Dudley Bose, observes the vanishing of a star. Since it is too far out to reach by wormhole, the startship, Second Chance, is sent to find out what happened. Will they find more than they bargained for?
11) The Mote in God's Eye by Larry Niven and Jerry Pournell SF NIVEN
12) A Canticle for Leibowitz by Walter M. Miller, Jr. SF MILLER & AD SF MILLER
13) Excession by Iain M. Banks SF BANKS
14) Starship Troopers by Robert A. Heinlein SF HEINLEIN (we also have the movie under DVD STARSHIP)
15) Do Androids Dream of Electric Sheep? by Philip K. Dick SF DICK (found within the book, Four Novels of the 1960s) & AD SF DICK (we also have the movie under DVD BLADE for Blade Runner)
16) Ringworld by Larry Niven SF NIVEN
17) 2001: A Space Odyssey by Arthur C. Clarke SF CLARKE (we also have the movie under DVD 2001)
18) The Forever War by Joe Haldeman SF HALDEMAN
19) Snow Crash by Neal Stephenson SF STEPHENS & AD SF STEPHENS
20) Neuromancer by William Gibson SF GIBSON
21) Hyperion by Dan Simmons (we have the first two books in the series under Hyperion Cantos) SF SIMMONS
22) Foundation by Isaac Asimov SF ASIMOV
23) Ender's Game by Orson Scott Card SF CARD & AD SF CARD & e-book
released in theaters on November 1st
24) Hitchhiker's Guide to the Galaxy by Douglas Adams SF ADAMS (the whole series can be found in The Ultimate Hitchhiker's Guide) & AD SF ADAMS & we also have the movie under DVD HITCHHIK
25) Dune by Frank Herbert SF HERBERT (we also have the movie Dune under DVD DUNE and The Children of Dune under DVD CHILDREN)
Once again, if you want to check out the article for yourself clink on this link.