The Five Love Languages
My relationship with my wife is my most valued asset. We're not perfect, and often we don't adequately express our heart's intent to each other. More than anything, I would say this book helped us learn how to communicate better by understanding the true motive behind each other's actions.
This book is full of wisdom. I now can not only can I "read" my spouse, but can understand better where my kids are coming from too. I highly recommend it as a way to become more "others focused".