1. Pragmatic Programmer
Many pearls of wisdom about the development process
2. The C Programming Language
Established the foundation for my early career
3. The Mythical Man-Month
Gave names to problems I'd experienced in my career.
4. Accelerate
Taught me the metrics and means of improving the software delivery process
5. Refactoring
Defined and named patterns for improving a codebase
There are others that could fit into a top 5 depending on what I'm working on at the time, (Gang of Four, Programming Pearls to name a couple).
