Either Ariel or Elsa

Yup. But also Mulan.

And Elsa.

Also Mulan. But most of the fans of Elsa force others to see her as they do.

Mulan, Ariel and Belle.

And Mulan and Elsa

This is my answer.

And Elsa and Ariel.

Or Elsa.

Oh my God!

also Ariel and Belle

Based on tumblr...Of course in there almost every princess gets appreciation so whatever.

Aside from Elsa, Ariel, Belle, Jasmine (for the fanboys, lol), Mulan, Tiana (only on tumblr I think?), and Rapunzel. People loved Merida when she first came out but it seems it has died off since then.

Definitely her and Mulan.

I'd say:

1. Ariel
2. Mulan (I've met more rude Mulan fans than nice unfortunately, and they're only from fanpop, but her base is a bit less defensive than Ariel's I think)
3. Elsa
4. Rapunzel
5. Belle (used to be #1 but I think Belle fans have calmed down over the years for whatever reason)
6. Tiana
7. Merida (when she DOES get love, they're very... strong about showing it)
8. Jasmine
9. Anna (unfortunately some Anna fans are also the same kind of rabid Elsa fans who think Frozen was super revolutionary in everything and praise her klutziness ardently)
10. Pocahontas
11. Cinderella
12. Snow White
13 Aurora (I swear I'm not being biased. I've only ever seen very chill Rose fans, and she has a pretty small fandom besides. The worst I've seen from them is some hate Snow)

Moana barely has fans over age 13 sadly.