Where to find the best science fiction short stories

I recently went looking for some collections of really top classic science fiction stories. Here's what I found.

If you're looking for a single volume, you probably can't do better than Masterpieces: The Best Science Fiction of the 20th Century. The collection covers a broad span of time, includes really big names, and the anthologist is Orson Scott Card, a highly respected author in the genre.

Beyond that, the ways part. The SFWA, the professional association of SF writers, got together in the early seventies and assembled The Science Fiction Hall of Fame, a collection of science fiction masterworks in three volumes, the first covering short stories and the other two covering novellas.

For more recent work, you might try The Best of the Best: 20 Years of The Year's Best Science Fiction by Gardener Dozois. Dozois was for a long time the editor of Asimov's, the top forum of the field for short fiction, as well as the editor of The Year's Best Science Fiction, an annual anthology of short stories. He has collected some of his top choices of more recent material in two volumes, one for short stories and the other for novellas.

And for even more recent material, there is Twenty-First Century Science Fiction, published in 2013.