Wthout any order:

"Code Complete" - Steve McConnell
Gives very interesting insights into software development in general. Something that I can only recommend everyone to read.

"Modern C++ Design" - A. Alexandrescu
Unleashes the C++ Template beast. If you ever wanted to know about policy-based design / generic programming this one is for you.

"Design Patterns" - GoF
Enough said about that book already.

"The Art Of Computer Programming" - Donald E. Knuth
This is indeed a piece of art. Highly abstract discussions about software. But be aware - no real code (except for Knuth's fictional MIX computer) and it contains quite some math (if you don't want to do maths programming certainly is wrong for you anyway).