Some writers and people who give advice to writers make a big deal out of a book's opening sentence, and of course it's true that a great opening helps pull a reader into a story. But of all the books I've read, I can remember the opening sentence of very few of them. Neuromancer has probably the only one I can quote from memory, at least that I can think of in the thirty seconds I'm using to write this post: "The sky was the color of television, tuned to a dead channel." That's a pretty good opening line.
Over at Speculative Faith is a list of openings lines from unpublished novels, and they're inviting readers to choose which ones they like best, and to offer critiques.