… in areas of recent interest to me.
John D. Cook on: R in Action and The Art of R Programming.
In short, The Art of R Programming is for programmers, R in Action is for data analysts, and most other R books I’ve seen are for statisticians. Of course a typical R user is to some extent a programmer, an analyst, and a statistician. But this comparison gives you some idea which book you might want to reach for depending on which hat you’re wearing at the moment.
Gaël Varoquaux on: NumPy 1.5 Beginner’s Guide
The book actually covers more than only numpy: it is a full introduction to numerical computing with Python.