Ugh. Once again a tough question :(. I'm just going to answer this with the first that popped into my head which is: Many Lives Many Masters by Brian Weiss. I've always been intrigued by soul mates and past lives, so I really enjoyed this book. Brian Weiss gives you his notes from some of his hypnotherapy sessions. It. Is. Awesome! I'm a psychology nerd though so I'm sure that helped me enjoy it that much more.