After reading John Gray’s original work and this, I was left with the feeling that not everything he wrote can be accurately explained as gender differences.  Many of his points sounded like differences in social styles and other personality dimensions not correlated with gender.  I have since consulted with our social styles trainer and she agreed with me.  Thus, I would not place this book high on your list.  However, I would not scratch it from your list altogether; I have observed some of the behaviors / reactions he described, so I found it useful to study the cause and effect regardless if gender may play a role (or not).