A store? Where you buy books? What a novel concept!
If you're a fan of Fantasy and SF, you've probably heard of Bakka. It's the oldest surviving specialty bookstore of its kind in North America, and even though it has moved fairly regularly over the past decade (it's about to move to its fourth location, but hopefully this is for good) it's carried that history with it.
You can find a great selection of books there, both prose and graphic novels, as well as a selection of used books and magazines. They carry both origina works as well as large selections of media tie in novels.
The staff there are acutely aware of what is published, and if you can tell them what you enjoyed they'll be able to point you at something else that'll be to your liking. Plus, many books have notecards explaining what they're about and what readers will find appealing about them.m
If you have any interest in sf books, you owe it to yourself to go here.