I have read probably a hundred relationship books, but there are only two that I love and can recommend without hesitation. They are:
How To Be Irresistible To Men by Amy Waterman: Amy Waterman is a relationship specialist whose methods have been features in psychology today. This book is absolutely the best at helping you pinpoint what you really want and who you really are. I firmly believe you can't attract the man you were really meant to be with (the real you) until you can do this. Amy offers a free e course which is excellent. You can check it out by clicking here and going into the women's website (she has one for men too).
Meet And Keep The Right Man by Naomi Miller: Miller had been a marriage counselor for 12 years. She's brilliant at making you see the common mistakes that you're probably making over and over that will sabotage your relationships each and every time. It's important to understand this because you don't want to meet "the one" only to let him get away by making preventable mistakes. There is an excellent free article on Naomi's website that tells you the 5 deadly mistakes many women keep making (I was making 4 of them! Whoops.) Check it out here. (You have to scroll down a bit to get to the article.)