(this page is always getting updated and forgotten...)
Between Silk and Cyanide: A Codemaker's War, 1941-1945", Leo Marks.
I thoroughly enjoyed this book and found it hard to put down. Here's the Wikipedia entry for Leo Marks.
Isaac Asimov. Click here for the Isaac Asimov home page.
Phillip K. Dick. Here's his Wikipedia entry.
Frank Herbert, author of Dune and the memorable
I must not fear. Fear is the mind-killer. Fear is the little-death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain.
Wikipedia for Frank Herbert is here.
Greg Egan, an Australian sci-fi author. Here is his official site.
Ben Bova, another sci-fi author I like. This page has some writing tips from Ben.
Neil Gaiman. I bought "American Gods" and was instantly hooked. Here's is Neil Gaiman's official site. "Anansi Boys" is a good read too, as are his other works.
Greg Bear, sci-fi author. His website is here.
Iain M. Banks, sci-fi. As Iain Banks he writes literary fiction. Official site here.
Stephen Baxter, another great sci-fi author (although I do admit I wasn't that crazy about Coalescent). Wikipedia entry here.
Neal Stephenson writes great stuff. Visit his official site.
William Gibson, often referred to as the father of cyberpunk. His site (with blog) is here.