Deep Survival, interesting read, studies what goes on in the minds of people who survive in extraordinary circumstances. I'm currently working on Guns, Germs, and Steel. The Right Stuff was a fun read, especially since my brother is a USAF test pilot.
I'm a huge sci-fi/fantasy fan. +1 for George R.R. Martin's Song of Ice and Fire series. -1 for Terry Goodkind's Sword of Truth series - one or two original interesting ideas, the rest is plagiarism and all of it is plain bad writing (though I have to hand it to him - I died laughing when I read the line, "Wizard's First Rule - people are stupid.") More good fantasy reads include The Black Company by Glen Cook, up to 9 books I think. Magic's Pawn, Mercedes Lackey, which is the first of The Last Herald-Mage series. Tigana, Guy Gavriel Kay. Black Sun Rising, first book in the Coldfire trilogy by C S Friedman. Patrick Rothfuss - The Name of the Wind.
Sci-Fi: A Fire Upon The Deep and A Deepness in the Sky by Vernor Vinge. The Reality Dysfunction, Peter Hamilton, 6 books. The Long Run, Daniel Keys Moran.
Genre-spanning: The Dark Tower series by Stephen King, opening with The Gunslinger.
Those are a few of the heavy hitters, the ones that enjoy almost universal acclaim by those who are voracious readers, the books I will continue to re-read every so often for the rest of my life. There's nothing like an old friend along on a solo trip.