I'm quality time, followed by words. Then touch.
I think touch might be higher on the list, but with regard to relationships at large, I reserve this mode of affection only for age-appropriate male friends. Sure, I'll dole out hugs when the social environment calls for it (family reunions, for example) - but I don't like to, and will absolutely avoid it if I can. I don't even feel completely comfortable hugging my own parents! If a friend accidentally bumps my foot under the dinner table, I pull away like I've been burned.
On the other hand, show me a dude I'm interested in/could become interested in...and I'll want nothing more than to touch him. Basically, I adore touch, but I've sexualized it.