Books I referred...

I started GMAT after my little bit of preparation for CAT, so my maths was well in place. So I didnt study maths as such from any of the books but kept solving problems from all the books.

There are lot of books available for GMAT prep and all are good. However, I referred the following books and loved them for the points mentioned:

GMAT Official Guide (OG): This is the book that every GMAT taker must have. The reason is very simple. It is the closest to the actual GMAT. I started with this book first and found it interesting. However, the explanations were very generalised and it is better that you refer this book in the last few weeks so as to keep yourself in the groove of actual test pattern.

Princeton Review: A great book for understanding the basics and to start with. Especially for Sentence Completion (SC). Most people have problems with SC and this book helps overcoming that. If you understand the types usually asked in GMAT from this book you will definitely score high on SC. CR tips and RC tips are great too. However, the full practise tests are not as close to actual GMAT (in my personal view). The AWA tips are great and should be used religiously.

Kaplan Premier: This is one of the toughest books for GMATprep. The SC, CR problems are great and so are the strategies. Is a good book for practise. And as they say GMAT is all about practise, practise and practise. If you are looking for toughest tests, refer the CD of this book. Four real tough tests, with a great feedback of every test.

Kaplan 800: The toughest problems ever. The problems are easily the ones which will keep troubling you till you understand the basic types and principles behind them. A must have book and should be used religiously. Keep practising it and your scores will excel. SC section has some additional types mentioned and that really helps in understanding SC problems in a better way. CR tips are good and if you are looking for toughest RC passages this book is happy to serve you with them. Another must have book.

I am not advertising any of the material and are my personal views in regards to the book.