TOP #1

Design Patterns: Elements of Reusable Object-Oriented Software

Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides
TOP #2

Head First Design Patterns: A Brain-Friendly Guide

Eric Freeman, Bert Bates, Kathy Sierra, Elisabeth Robson
TOP #5
TOP #6
TOP #8

Refactoring: Improving the Design of Existing Code

Martin Fowler, Kent Beck, John Brant, William Opdyke, Don Roberts
TOP #11
TOP #14

Pattern-Oriented Software Architecture Volume 1: A System of Patterns

Frank Buschmann, Regine Meunier, Hans Rohnert, Peter Sommerlad, Michael Stal, Michael Stal
TOP #15
TOP #17