The Graduate Management Admissions Council (GMAC), is the author of the GMAT and publishes an official review guide. This book is recommended because it most closely previews the questions that will be asked on the actual exam. GMAC also makes review books that focus on each of the sections.
Kaplan is a popular test prep publisher, with books for nearly every admissions exam. Kaplan's GMAT books focus on teaching problem-solving strategies that can be applied to the various types of questions that can appear on the GMAT. This is a good book for those who would like to apply a general method to any problem.
Princeton Review's GMAT books differ from Kaplan's in two important ways: First, the practice tests are not as difficult in the Princeton books. Second, Princeton Review focuses on finding the shortest way to answer each question rather than providing a general method.
The Manhattan Review GMAT prep books differ from Kaplan and Princeton Review in two ways: First, Manhattan Review contains a large GMAT vocabulary list in the verbal section book and a quantitative glossary in the mathematics book. Second, the method not only explains how to solve problems, but elucidates the different concepts and exercises.