Sex for me is a language, and an energy, and each person I am sexual with has their own sexual "fingerprint". It is this unique expression that is meaningful for me, not any particular act or expression. The way one partner performs oral is vastly different in energy, intent and skill than another. The shape of someone's body (or their gender) lends expression to how they touch and move with a partner. A lover's age and experience level make them special at a particular place and time. Above all, sex is, for me, a way of exchanging love in a very pure form -- one that doesn't necessarily need a longterm commitment (though it does require trust) and one that should leave each person feeling nourished, cherished and full of joy.
VERY good question.