A number of you have asked me about my favorite SF novels and writers. Actually, nobody has asked me, but I am going to tell you anyway because it's my blog and I can do anything I want. Hahaha! Such a feeling of power. Napoleon should have written a blog. It would have kept him out of trouble.
As you might have guessed, my tastes run strongly toward so-called "hard" science fiction -- stories with a very high science content. Even more specifically, I'm a fan of "idea" stories, in which the idea plays the central role. Orson Scott Card, in his book How to Write Science Fiction, claims that science fiction can be classified on the basis of how much each of the following four elements dominates the story: milieu, idea, character, or event. He calls this the MICE quotient. It's a useful way to think about science fiction. The fact that I like "idea" stories also means there is a strand of hard science fiction that doesn't really appeal to me at all -- stories you might call "engineering fiction." These are the stories that really delve into the nuts and bolts of some technical problem. The protagonist has to think of a clever way to solve the problem in order to save the spaceship, escape from the planet, etc.
When I was young (recall that the Golden Age of Science Fiction is 12) my favorite authors were (as you can probably guess) Isaac Asimov and Arthur C. Clarke. The third name that always comes up in connection with those other two is Robert Heinlein, but I wasn't as much of a fan. Now that I am older and have actually tried writing SF myself, it's obvious that Heinlein was actually the best writer of the three. And Clarke had the most far-ranging, interesting ideas (although his short fiction far outshines his novels). As for Asimov? Volume, volume, volume! But he was for many years my favorite writer (of both fiction and nonfiction).
A bit later I really enjoyed the Known Space series by Larry Niven. But more recently (and by "recently" I mean the past 20 years), I've read three novels that were far and away my favorites. Two of them are the Vernor Vinge linked novels, A Fire Upon the Deep and A Deepness in the Sky. The first of these is an outstanding space opera with sweeping scope and amazing ideas. The second is that very rare beast, a sequel that actually outshines the original While it lacks the scope of the first book, A Deepness in the Sky provides much more interesting character development, an amazingly well-developed alien race, and a much tighter plot. So I guess A Fire Upon the Deep is Vinge's version of War and Peace, while A Deepness in the Sky is Anna Karenina.
The third novel that makes my "top 3" list of the past 20 years is Robert Charles Wilson's Spin. I'm not even going to bother summarizing it - if you're not familiar with it, then just get a copy right now and read it. The sequels, unfortunately, are not as good as the first book. If you like Spin, I think Wilson's second-best novel is Darwinia.
In the arena of short fiction, my favorite "recent" author is Greg Egan. He is the ultimate "idea" author -- his short stories present some of the most original and creative ideas I've ever seen. I'd recommend his short story collection, Axiomatic, if you can get a hold of it. One possible issue: to really appreciate some of his fiction, it helps to have a Ph.D. in physics. His novels are not quite up to the standard of his short fiction, but I did like Quarantine (which plays with some of the spookier aspects of quantum mechanics) and Diaspora.
And while I am not a fan of fantasy in general, I enjoy the works of Tim Powers. He creates fantasy worlds with quirky but logical rules -- almost the fantasy version of hard science fiction. It's difficult to explain this more clearly -- you just have to read his books. The Anubis Gates is probably the best, but all of his novels are worth reading.