Neuromancer? lol that's the only cyberpunk book I've read that I can recommend. I've also read Rainbow's End but I was bored the fuck out of it.
In Sci-Fi in general I recommend Ender's Game of course. But a lot of people have already read that. Despite my affinity for Sci-Fi in general I haven't read to many Sci-Fi Books (something I plan on changing)
Wait, Fahrenheit 451 is technically Sci-Fi and is also good. Also the only 3 Sci-Fi Stephen King books I've read (and I think all he has) "Cell", "Under The Dome", and "Tommy Knockers" None of them are set in the future, just have sci-fi focus'ed story elements. Cell is the best of those in my opinion, but its zombie apocalypse so that's why I like it so much, Tommy Knockers is an alien invasion story, Under The Dome is at first only vaguely sci-fi until more is revealed, its about a giant force field dome that mysteriously appears and traps an entire town.