I was browsing an artsy bookstore in the city today- and got in to a conversation with someone on what their all-time top 5 favourite books would be. I'm not sure about the order - but here are mine. (and yes - I do read other books besides SF - but this is what I like most)

1. Cloud Atlas by David Mitchell - weird and disjointed but just so damn good

2. The Sparrow by Mary Doria Russell - I wouldn't think a story of ET contact and the catholic priesthood could move me so much - very hard to describe without it sounding dumb - but a great read

3. A Fire Upon the Deep by Vernor Vinge - The best massively imagined Space Opera ever written

4. Oryx and Crake - Margaret Atwood - Depressing in its dystopian vision, but so well thought out and realized.

5. The Yiddish Policeman's Union - Michael Chabon - I don't usually go for the alternate history type books - but the cold Sitka Alaska setting really works for me. The Coen Brothers are making this into a movie.

Honorable Mention: Titan by John Varley because I read it in 8th grade and still read it every 5 years