Bruce F. Webster's "Pitfalls of Object Oriented Development"

We got too many "OO" developers who still don't know what an object or a class is or what is for; don't know what good OO, procedural, modular and structured programming look like; and somehow manage to cobble badly made pseudo-procedural code together with classes.

This book (plus a few 70's oldies on structured design) would go a long way in helping these poor souls finally get to understand what good object orientation should look like.

Furthermore, chances are that if I were forced to pick one book and one book only beside this one, I would not pick a technology-specific book.