Effective Java by Joshua Bloch — THE book for honing your Java-fu. If you haven't read this, stop reading and go buy it now. There's so much good stuff in this book, I savored it over about three months.
Peopleware: Productive Projects and Teams by Tom DeMarco and Timothy Lister
— A classic in software development management. Much of what Joel Spolsky has used to build Fog Creek and which he writes about is derived from this book. A warning though, if you work in a cube for a large company, you will probably be tempted to quit :)
Groovy in Action by Dierk Koenig, Andrew Glover, Paul King, and Guillaume Laforge — Groovy is a fantastic language, built around the desire to be useful and productive. This is a good introduction from some of the project leads. I would like to have more content on Groovy's metaprogramming capabilities. The MarkupBuilder section of the book was very handy when I was re-implementing a mess of a Java/XSLT report generator, ending up with about half the lines of code and far greater readability.
The Productive Programmer by Neal Ford — Following in the tradition of "The Pragmatic Programmer", this book provides a bevy of ideas of how to improve your programming. The treatment of many of the subjects is relatively shallow, but everything from window launchers to code coverage is somehow hit. Ford also mentions specific software packages various tasks, which takes the great risk of quickly dating the book but makes it much more useful for the reader.
Differentiate or Die: Survival in Our Era of Killer Competition by Jack Trout and Steve Rivkin — I was hoping for a book on how to differentiate your product in the marketplace based on creating innovative products, but this is more "how to lie to people about your product when it's just like everybody else's." "It's Toasted" indeed.