As much as I love Ender's Game I've turned my head away at it since I found out that Orson Scott Card was an extreme right-wing mormon. While I don't like to attribute a book's content to it's author I feel like this sort of ruins a bit of the book's magic.
Hackers: Heroes of the Computer Revolution was an excellent read and then of course you can't go wrong with Douglas Adams. Excellent stuff.
The absence of the Jargon File / Hacker Dictionary must be noted, and ideally, corrected.
Gödel, Escher, Bach would seem to belong as well.