That was easy to answer and I thought of it right away even though Disney is known for their beautiful princesses.
When I saw her on Tangled at first I was like "Meh, she's just like the other princesses..." but then as some scenes came and passed, I found myself saying "Wow...she's stunning." Her eyes-beautiful shade of green, her eyelashes- just perfect and of course her beautiful long hair. I'm not too fond of the short look at the end but because of the reason, it still works for me!
If I had a second, it would be Jasmine.