Authenticity - more than simple honesty, it is a willingness to let someone in, be vulnerable and know that Child in all of us. I once heard it put very well. “If you share with me what you hate about yourself, I will Love it for you.”
In my opinion, the most important part of a relationship is COMPATIBILITY. None of this opposites attract stuff for me. I want her to be like me, open minded, witty, free thinking, passionate, affectionate, honest and forthcoming.