Among the actual Disney princesses, it would have to be Snow White. (I'm a bit surprised that it isn't Ariel, although she would be my second choice, as I wanted to be a mermaid when I was a child. Perhaps it is because Ariel didn't want to be a mermaid.) Snow White is so feminine and takes so quickly to being the lady of the house (love the Bavarian decor, too). And who wouldn't want to fall asleep and be awakened by a kiss from a handsome prince?
If Alice were a princess, she would probably at least tie with Snow White, as I regard Disney's Alice in Wonderland as a tutorial in femininity - yessss, your majesty!