Kaplan GMAT 2008: Premier Program is designed to maximize a student’s score on the GMAT, including an accompanying CD-ROM with additional questions and tests, as well as an interactive online study planner that provides fresh practice questions every month and quizzes that can be downloaded to PDAs and cellphones for test-prep anytime, anywhere.
This comprehensive, up-to-date guide also presents Kaplan’s exclusive test-taking strategies for achieving a higher score, as well as an online diagnostic test to target areas for score improvement. No serious test-taker should be without it.

The important section here is a comparative assessment of the major books, so that the applicant saves time searching for too many books, here is an unbiased opinion about the advantages and disadvantages of the popular books.

 

The Official Guide for GMAT Review: 
Advantages: 
- More than plenty of practice questions
- You might get the same or similar questions on the GMAT (like I did)
- The practice questions are organized by level of difficulty, the last ones are the most difficult
- Free PowerPrep software that has two practice tests exactly similar to the GMAT in look and feel

- The practice questions reveal actual GMAT test patterns
Disadvantages:
- Absence of test taking techniques
- The skills review sections are poor
- Only the last 200 questions in every practice section will be like the ones you will see on the GMAT (unless you perform poorly)

Princeton:
Advantages:

- Good review sections (both quantitative and verbal)
- Practice tests are similar to the GMAT
- Online tests are easy to review
- Provides with a test strategy on how to crack the questions
- Explicitly advises to practice also with The Official Guide for GMAT Review
Disadvantages:
- Does not explain why a choice is wrong
- Not enough practice questions

Kaplan:
Advantages:

- Good quantitative review sections

-Appendix is great
- Interactive software for reviewing the Kaplan GMAT strategies
- Practice tests similar to the GMAT
- Practice tests and sections are difficult, this creates in a sense of urgency
- Plenty of practice questions
Disadvantages:
- The software interface is old and slow, you are left to work with a little box on the screen
- Practice tests and sections' answer choices are not very well explained
- The questions are far fetched and do not fall in the spirit of the GMAT, this might lead you the wrong path