Excellent Tuning Book
Many of the other books talk about theories or are a regurgitation of the Oracle documentation. This book is different. This is a no-nonsense guide to Oracle performance tuning. The organization of the book makes it excellent to read but is packed with enough information that makes it an excellent reference. Both of Gavin's books are Golden. This book deals with the traditional OLTP type system. His DW tuning book is also excellent and deals with DW type systems. I would recommend getting both as they cover the correct application of Oracle technologies to solve specific problems that you might face as an application developer, architect, or DBA.
Oracle Performance Tuning
Quite good and well summarised information with included scripts and comments for them.
