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This is a poll asking the Stackoverflow community what non-programming books they would recommend to fellow programmers.
Please read the following before posting:
Please post only ONE BOOK PER ANSWER.
Please search for your recommendation on this page before posting (there are over NINE PAGES so it is advisable to check them all). Many books have already been suggested and we want to avoid duplicates. If you find your recommendation is already present, vote it up or add some commentary.
Please elaborate on why you think a given book is worth reading from a programmer's perspective.
This poll is now community editable, so you can edit this question or any of the answers.
Note: this article is similar and contains other useful suggestions.