No one can ever call her plain or boring, either for personality or looks.

Or Ariel.

She spiced things up a bit after the Classic DPs, and set the ball rolling for the Renaissance and Modern DPs

I think of Mulan as a strong woman it just fits...

I guess. She was the first one who had more personality that was just elegant and nice. She is the reason why women are portrayed the way they are today, and she did change how Disney dealt with women ever since.

At least, all the newest princesses "copy" her personality/look.

* Rapunzel - cheerful, spirited, excited, naive, hopeful (not as dreamy as the three oldest princesses)
* Merida - red-headed, blue-eyed, green as her main color (Ariel's tail is green), adventurous, stubborn.

And Ariel :)

She changed the definition of a Disney Princess, looks and personality.

Far from my favourite but after the classic Princesses she was something entirely different.