[VIDEO]http://www.amazon.com/Fire-Upon-Deep-ebook/dp/B000FBJAGO/ref=sr_1_1?ie=UTF8&m=AG56TWVU5XWC2&s=digital-text&qid=1296552553&sr=1-1]Amazon.com: A Fire Upon The Deep eBook: Vernor Vinge: Kindle Store[/VIDEO]
or really, anything
by Vernor Vinge.
[VIDEO]http://www.amazon.com/Schilds-Ladder-ebook/dp/B000FC2NY4/ref=sr_1_1?ie=UTF8&m=AG56TWVU5XWC2&s=digital-text&qid=1296552694&sr=1-1]Amazon.com: Schild's Ladder eBook: Greg Egan: Kindle Store[/VIDEO]
Egan's book are a bit on the "hard" side of sci-fi and several people can't stand him, but I think all of his books are great.
A short story written by Egan that demonstrates his style pretty damn well -> http://www.99chan.in/lit/src/Reasons-To-Be-Cheerful.pdf