Design Patterns   (book)

Design Patterns: Elements of Reusable Object-Oriented Software

Design Patterns is by many accounts as close as you can get to Object Oriented Programming's Bible... I'm not an avid user of the languages that these patterns are designed for, so I didn't really "get" the advantages that using these types of patterns give, since I can just take them for granted in most cases. Nonetheless, it was a good read overall.