Books for Java CertificationThe Latest
Sun Certified Programmer & Developer for Java 2 Study Guide by Kathy Sierra, Bert Bates is the latest book on Java Certification. If you are preparing for SCJP 1.4, this new book is the best buy. It is created by the founder of Javaranch and covers the latest version of the exam.
A Programmer's Guide to Java Java Certification by Khalid Azim Mughal, Rolf Rasmussen is the best book on Java Certification. Its standard is slightly above the actual exam, hence it can give you more confidence. It is also a good reference book after you have cleared your certification.
The most popular
Complete Java 2 Certification Study Guide by Simon Roberts, et al is a very well known book on Certification and probably the most popular book on the subject.
Java 2 (Exam Cram) by Bill Brogden, William B. Brogden is another popular book.
Java 2 Certification Exam Guide for for Programmers and Developers by Barry Boone, William Robert Stanek. This book is selling for $24 at amazon a discount of 60%.