Books You Can't Do Without -- The Very Best You've Read

Lets talk about the IT books we've read , only the best please .
We can categorize them by subject matter .
For me, these books were eye openers
Here's my list

Java Programming
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Thinking in Java - Eckel
Effective Java - Joshua Bloch

C#
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Seeing data - Rebecca Riordan

DB
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Java database best practices - George reese

Windows programming
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Programming Windows - Charles petzold

Design
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Refactoring to patterns - Martin Fowler
Head first design patterns - Eric Freeman

Mix
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The secret guide to computers - Russ Walter

Java Programming
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Java How to Program Deitel Deitel

Linux
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H.a.c.k.e.r.s Guide to Linux (can't rem d author)