I'll throw .02
I enjoy them all, but I chose Ariel because she ushered in a new era of Disney movies. She (Thee Little Mermaid -1989) began a growing trend of girls being associated with Princesses. Personalities, hair colors, living styles and great stories.
Since '89 we have seen Ariel, Belle, Jasmine, Pocahontas, Mulan, Rapunzel, Tiana, Merida, and now Anna and Elsa.
I graduated from HS in 89 and it was the beginning of my own trips to Disney.
My Daughter was born in 2000 and it was not too difficult for her mother and I to agree on 'Ariel Renee' as her name. We both loved the movie and thought it flowed well.
Maybe more than you wanted to know, but that's my reasoning.
So that is ....The Rest of the Story.