In the last few weeks I've read a few of the more famous "libertarian fiction" works—Henry Hazlitt's Time Will Run Back, and Garet Garrett's The Cinder Buggy and The Driver.
Hazlitt may have been a good writer, but he had no skill in fiction. The characters in Time Will Run Back are pathetically two dimensional, and the plot is contrived and generally abysmal. Worst of all, the entire book is merely a conspicuous vessel for pedantic "discussions" about good economics. And even those discussions are of limited value—if you want lessons in economics, there are many better options. And whatever you do, don't read this if you're looking for fiction that isn't painful to read.
Garrett's works are much better. There's less pedantry, and where it exists, it provides helpful background to the story. The characters are, for the most part, believable, though sometimes it seems like Garrett had just finished The Idiot or The Brothers Karamazov when he sat down to write The Cinder Buggy—some of his characters act almost as irrationally as Dostoevsky's. Even so, The Cinder Buggy is a good book, and so is The Driver. Both have interesting, strong protagonists who work tirelessly to achieve their visions.
There's an interesting article on the Mises blog, entitled, "Ayn Rand and Garet Garrett," discussing the similarities between Rand's Atlas Shrugged and Garrett's works, especially The Driver. The obvious similarity is the last name of the protagonist (Galt), but another one that struck me was the use of a courtroom scene to vindicate the protagonist (Garrett uses it for Galt, Rand for Rearden). Nothing close to plagiarism, but interesting nonetheless.