Chandler-
-Your style
-She appreciates a well-dressed person ;p
Duke-
-Your interest in things she talks about
-Most people could care less about what Duke talks about (*couch cough* chandler *cough cough*), but you actually care, which makes her happy
McNamara-
-You smile
-Your smile lights her up, making her feel better on a bad day, and warming her up on the inside
Veronica-
-You hair
-She likes pushing her hand through your hair, and (if you have long hair that reaches longer than her hair) she likes to push your hair behind your ear
JD:
-You eyes
-He likes to stare into your eyes
-He thinks they're beautiful