ExamKrackers probably has the best prep books for MCAT. It covers all the topics on the MCAT, and explains the concepts quite well. So far, I haven't had the need to use textbooks. They also have a very attractive layout of the material that makes reading enjoyable. I also appreciate that it comes with a full MCAT past paper, in addition to the multiple practice questions already in the books.
If you had to choose just one prep company to go with, go with ExamKrackers.