Both: Hands♥, Necks, Lips, Ears and Noses. I don't know why, but if someone has a really... unattractive nose, I can't look at their face right. They could have the face of an angel, and their nose be too fat or skinny or that big bump in it, and I can't... be comfortable looking at their face.
And yes, Hands make me happy. God, I dunno why. Hands are special to me. ♥
Ladies: Boobs, seriously. The curves are gorgeous. And the Thighs, oh goodness. ♥
Men: Arms & Shoulders. Also, Jawline. ♥ Nothing better than a man with strong arms and shoulders.