So far, it could be argued that there is a startling omission of women writers here. It would be untrue to pretend that women have not had a profound effect on science fiction. It could be argued that the large percentage of great science fiction writers who have emerged since the 1970s are women. In fact, it has been argued (to me by several women writers and scholars).
1) Falling Free by Lois McMaster Bujold
2) Downbelow Station by C.J. Cherryh
3) Cyteen by C.J. Cherryh
4) Impossible Things by Connie Willis
5) Star Man’s Son by Andre Norton
6) The Handmaid's Tale by Margaret Atwood
7) The Female Man by Joanna Russ
8) Native Tongue by Suzette Haden Elgin
in Canopus : Archives by
Doris Lessing Argos
10) The Xenogenesis Trilogy by Octavia E. Butler
Of these books, the best is, in my opinion, Native Tongue. This explores linguistics and feminism in a dystopian setting and came about as a "thought experiment," which, I like to think, probably most of the best science fiction is wont to do.
The most controversial is easily The Female Man, for being the first blatantly feminist novel to make a big splash in SF (and piss off some male writers, apparently, or so I've heard...from some of those male writers).
Cherryh is by far and away the most prolific of these authors, and she has developed a legion of fans. The two books listed for her are often considered to be her best, and most important. Both books, set in the same universe, are excellent examples of space opera.
Bujold is among the most celebrated SF writers around, and Falling Free is widely regarded to be her most inventive book (also one of my favorites), and catapulted her into the stratosphere of science fiction authors.
Impossible Things is a short story collection, which reflects the fact that Connie Willis is considered to be one of the absolute best short form SF writers, ever.
Andre Norton is one of the most prominent female authors in the field, although her influence has primarily been in fantasy. But her SF is important, expecially in juvenile fiction. Star Man’s Son is a classic juvenile and is important in showing that Heinlein was not the only successful voice in that world.
The Handmaid's Tale was published as a mainstream literary novel, and the author denied that it is "science fiction," instead calling "speculative fiction" and differentiating it from science fiction because it was "possible." Call it what you will, the definitions overlap, and frankly the labels "science fiction," "SF," "sci-fi," "specfic," "speculative fiction," "scientifiction" and "science fantasy" are all marketing terms anyway. Like Vonnegut, Atwood brings true literary recognition to the genre, intentionally or not.
One criticism of mainstream authors who write science fiction tends to be that their lack of knowledge of what has come before means that they tend to recycle old ideas and use genre cliches. While this may be true, it could also be argued that their perspective as "outsiders" to the genre allows them to approach such otherwise tired old ideas from new directions, breathing new life into them.
Doris Lessing is primarily known as a literary writer, and her SF is sometimes considered to be sub-par (as science fiction, but not as "literature"). But her Canopus in Argos books cannot be denied as literary classics with an SF bent.
Octavia Butler has emerged as one of the most influential writers around, and she has two series that have really had an impact on the field. Her other one is the Patternist series. It could be argued that this one is more prominent than the Xenogenesis trilogy. But I feel Xenogenesis best displays
originality in exploring tried-and-true SF ideas from her unique perspective.