Not all of the ones below may be textbooks, sorry, but IMO they are all very good. I cut my programming teeth on some of them, and read others at different times later in my career.<p>How to Solve It, by Georg Polya.
A famous Hungarian mathematician.
A text on general problem solving principles or techniques. A classic.<p>How to Solve It by Computer, by Dromey, an AU CS professor. In the same spirit as the Polya book, but applied to iteratively working out algorithms and pseudocode for common important programming problems.<p>The K&R C book. What to say.<p>The Unix Programming Environment, by Kernighan and Pike. Ditto.<p>Programming Pearls, and More Programming Pearls, by Jon Bentley.
Among many other things, some clever / advanced uses of awk.<p>Writing Efficient Programs, also by Bentley. I had mentioned it on HN earlier, and someone replied saying they had used it in real life, and it was gold.<p>SQL for Professionals, by authors whose names I forget.<p>The Object Primer, by can't remember who, but good.<p>A Unix book by Kochan, IIRC.<p>Object-Oriented Software Construction, by Bertrand Meyer, creator of the Eiffel programming language.<p>A book on object-oriented analysis / design, can't remember the name, by Rebecca Wirfs-Brock (?) and others. Learned about CRC cards from it. Very cool concept and technique.<p>A book on Object-Oriented Design, by Grady Booch, from a time before he co-invented UML. Forget the exact name.