For those looking for some additional recommendations that are "literary" (by which I mean, densely allusive and layered with meaning, yet not painfully self-conscious or lacking in any sense of awe and wonder, let alone enjoyment), look into Gene Wolfe. He is not exclusively a science fiction author, but The Book of the Sun (a tetralogy) and the rest of the Solar Cycle books definitely are, and they remain among my favorites. The entire series will keep you busy for a while. For a shorter introduction, consider The Fifth Head of Cerberus, consisting of three related novellas, is exquisite; also worth checking out.
See also, Borges; not usually considered a science fiction author, I suppose for reasons having to do with the connotations of being a genre author.
I've been reading the Book of the New Sun for the last couple of weeks, and I can second this recommendation. It straddles a very interesting line between science fiction and fantasy, and it definitely feels like a piece of literature more than most works of either genre. As I recently explained it to a friend of mine, it's "Dune caliber" (though not at all similar in terms of setting). A great read.
See also, Borges; not usually considered a science fiction author, I suppose for reasons having to do with the connotations of being a genre author.