Art of Computer Programming
The ultimate in computer science books. Only the first 3 of 7 volumes are complete, because Knuth got Babbage Syndrome and had to fix typesetting by inventing TeX first. The Art of Computer Programming Reading Group exists to help those who are having trouble reading it all in one sitting.
Code - The Hidden Language of computer hardware and Software
Fantastic book. Begins at data representation (morse code, braille, even bar codes!), proceeds to logic circuits, building full binary adders (with an explanation of how to do subtraction without borrowing), through to memory circuits, through to computer control using machine code and assembly.
Makes you want to break out that old electronics kit and start soldering. 10 (binary) thumbs up!
About Face 3 - The Essentials Of Interaction Design
Excellent introduction to interaction design. Advocates goal-directed design.
The Pragmatic Programmer
A book about becoming a more efficient programmer.
A book about software construction. More general than Pragmatic Programmer. Loads of information on how software development projects should be run, with research citations to justify approaches.