Harold Abelson and Gerald J. Sussman, with Julie Sussman: Structure and Interpretation of Computer Programs, 2nd ed., MIT Press, 1996.

(Also available online.)

The best book I know for learning how to think about programs.

Bertrand Meyer: Object-Oriented Software Construction, 2nd ed., Prentice Hall, 1997.

An excellent introduction to the creation of high-quality (object-oriented) software.

Richard Mitchell and Jim McKim: Design by Contract, by Example, Addison Wesley, 2002.

An excellent discussion of the principles of design-by-contract, with many examples (in Eiffel,  some also shown in Java).  After you've read Meyer's book, read this one for a more thorough discussion of design-by-contract.

Daniel P. Friedman, Mitchell Wand, and Christopher T. Haynes: Essentials of Programming Languages, 2nd ed., MIT Press, 2001.

An advanced investigation into the principles of programming languages, interpretation, and compilation.  Uses program transformations as essential tools.

This is the book to turn to after you have mastered Abelson and Sussman's Structure and Interpretation of Computer Programs.

As an OO developer, you will find yourself professionally handicapped if you don't know what design patterns are and how to use them.

This is not a book to read from cover to cover; instead, you need to know what it contains, and refer to specific patterns as you need them.  Patterns are properly learned only by using them for solving real problems.

Regardless of which methodology you use, this is something you need to do.  Read the first five chapters to know what refactoring is; then use the specific refactorings in the rest of the book in your daily work.

Donald E. Knuth: The Art of Computer Programming, 3 volumes, Addison-Wesley.

Everything you always wanted to know about algorithms...

A list of 57 items on the proper use of Java.  If you don't know these, you can't call yourself a serious Java programmer.

A list of 95 puzzles with important lessons on the proper use of Java.  An excellent companion to Effective Java.  Contains material on the new Java 5 features.

Why can't we use the hold feature in our phones, find the correct light switch in an auditorium, open doors in public places?  Read this book to be enlightened.

A short but penetrating explanation of what is wrong with most web sites you see and how to do it right.

If you enjoyed Don't Make Me Think and want to get deeper into the subject, this is the next step.

(Also available online.)

A modern look at ethics in Computer Science, using a series of thought-provoking stories.

An analysis of many computer-related failures, including some of the most spectacular ones, and recommendations on how to avoid such risks.

A masterpiece, exploring the relationships between art, computer science, and artificial intelligence.  Well-worth the time.

An in-depth investigation of object-oriented programming languages, comparing the most influential languages today.

A collection of Bentley's columns in CACM.  Each pearl is an essay about programming well.  A book to read and re-read.

Be on the lookout for the second edition of the second volume.

This 1971 classic has been reissued with new commentary from the author.  Still as fresh and relevant as the day it was written.  Entertaining as well as thought-provoking.

An essential book for you to understand yourself as a professional programmer (even if you call yourself a "software engineer").

An exposition of user interface from the author of the Mac GUI.  You will never design user interfaces the same way after reading this book.

If you want to develop intelligent tools in general, and for software engineering in particular, this is a must read.

M. R. Lowry and R. D. McCartney (eds.), Automating Software Design, AAAI Press, 1991.

A fascinating description of the development of Data General's 32-bit Eclipse supermini under an impossible deadline.  The computer itself is obsolete, but the human factors haven't changed a bit.

A story of the 1960s software hackers at MIT, the silicon valley hardware hackers of the 1970s, and the game hackers in the 1980s.  An interesting look into three related but different cultures, which have had a great influence on the profession, for example, on the open software movement.  (The word "hackers" here is used in the original, positive sense of a wizard programmer.  See also the Hacker's Dictionary below.)

A 75-cent accounting discrepancy that led astronomer-turned-programmer Cliff Stoll into a long chase that finally led to a group of German hackers (in the bad sense of the word) looking for sensitive material to sell to the KGB.

Essential reading for anyone interested in writing high-quality theses, papers, or other documents.  Also very entertaining, unlike most books of this kind.

Short and concise writing instructions, if you don't have time for reading a longer book.

Contains "The Story of Mel, a Real Programmer", among other gems.

This is a collection of articles about what it means to be an engineer, written for IEEE Spectrum.  They are certainly funny, but they contain barbed truth nonetheless!