The Princeton Review is a well-known test preparation and college admissions consulting company that offers a variety of books to help students prepare for standardized tests such as the SAT, ACT, GRE, GMAT, and more. Their books typically include practice tests, study tips, and strategies for success on the exam. Some popular Princeton Review books include "Cracking the SAT," "Cracking the ACT," and "Cracking the GRE." These books are widely used by students looking to improve their test scores and gain acceptance to their desired colleges or graduate programs.