The Best Space-Travel Science Fiction Novels
Dan Simmons: Simmons has written other works, but conversation always comes back to The Hyperion Cantos and rightfully so. Four novels, spanning hundreds of years, set in the far future of a galaxy spanning human empire. It has a sense of poetry that is the envy of most science fiction; it is a meditation on the nature of the universe and man's place in it as much as it is about starships and time travel.
Isaac Asimov: Asimov's three great trilogies (Empire, Foundation, and Robots) all end up connecting together into the same fictional universe in later books, but it was always Foundation that touched me the most. Asimov wrote no aliens into this universe (a fact he explains in another related story), but the exploration of different human societies, of trudging through a graveyard of our own grandfathers, that is awe inspiring stuff.
Alastair Reynolds: He tends to write very hard science fiction, and his most famous books (the Revelation Space series) are very slow moving, but ultimately extremely satisfying. But as a starting point? Pushing Ice is a beautiful stand alone book that tells of the first humans to travel beyond the solar system, a simple mining vessel caught up in the wake of an alien craft just passing through our little corner of the universe.
John Scalzi: Old Man's War and its subsequent sequels are fantastic forays into military science fiction with a philosophical bent. Who are we if not our memories?
Vernor Vinge: He's not the most prolific of science fiction writers, but when he nails it, he nails it. A Fire in the Deep and A Deepness is the Sky are both fantastic stand alone stories, of man tentatively exploring the vastness of the universe.
Robert Heinlein: He's the godfather of them all. Not all are based on space-travel (and some of his most famous like Starship Troopers are the weakest, but Stranger in a Strange Land and various Lazarus Long novels are mandatory reading for the budding science fiction reader.
Elizabeth Moon: She's written rather prolifically, and has two science fiction series in particular of note: The Serrano Legacy and The Vattas. They're not deep and profound like much of the rest of the list, but they are quick reading and quite fun.
Philip Jose Farmer: Okay, Riverworld and its sequels are not space-travel, but they technically take place on an artificial world in the distant future and feature aliens. That's close enough to get these absurdly creative books on the list.
Stephen Donaldson: The Gap into Conflict is all space-travel and is one of the darkest science fiction series that I have ever read. Under the aliens and space-travel and horrifying events inflicted on its characters is a meditation on the nature of power.
Simon Green: Green's Deathstalker novels are the guiltiest of guilty pleasures. They're all swashbuckle and dashing between stars, with contrived technological context so as to preserve the constant need for sword fights. From one point of view, these novels are terrible. From another point of view, they are so much fun that they don't need to be good.
Jack Campbell: A lot of space opera leans towards the military science fiction, and most of that is not particularly good. They tend to spin out endless sequels, each more fascist than the last, all the while badly imitating Startship Troopers without any of the verve or irony. Campbell avoids these cliches, and although his extended series get a bit long in the tooth, his initial series crossing The Anabasis and the myth of lost kings is fantastic.
Charlie Stross: Stross gets around within the science fiction sub-genres. He's got his Merchant Princes alternate universe series, The Laundry series that integrates spy novels and Cthulu, and he has a whole pile of other stand alone novels set in space-travel. Singularity Sky and Iron Sunrise are the best of these, and possess a humor too often in absence in science fiction.
Jack McDevitt: His best work is A Talent for War, and any reading should start there. Despite the title, it isn't a military science fiction novel at all, but a historical mystery set thousands of years in the future.