Particularly because she gets over her Squick at being a frog and embraces the utility of her condition.
"Friends On The Other Side" is Dr. Facilier's crowning moment, especially at the end when he tells Naveen to blame "my friends on the other side".
Also, a crowning moment for the animations: just watch Facilier's dance?
Another Crowning Moment for Facilier would be when his shadow stops Tiana from destroying the talisman (the first time she tried).
Dr. Facilier's temptation of Tiana in the climactic scene is a crowning moment for them both — for the villain, his Breaking Speech (how could it be otherwise when delivered by Keith David?); for the heroine, her Kirk Summation response as she moves to destroy his talisman.
Tiana: My daddy never did get what he wanted. But he had what he needed. He had love! He never lost sight of what was important! And neither. Will. I!
Terrifying though it may be, no one can debate that "The Friends On the Other Side" Reprise wasn't a CMOA. Besides seeing Dr. Facilier reach his villainous comeuppance, it's so awesome to see his puppets, his Shadow Demons, and even his voodoo symbols turn against him in this final scene.
The whole movie qualifies since it shouts "Disney's back!" as loudly and awesomely as The Little Mermaid did 20 years ago. History does indeed repeat itself.
And the fact they managed it using one of the most classic fairy tales: taking an old and over-used story and telling it in a way that still makes it a good and pleasant story is nothing but awesome storytelling.
Visual Effects of Awesome: The beautiful sequence accompanying "Ma Belle Evangeline". Pond ripples, glowing flowers, Ray's light show...
Tiana finally buying the warehouse — racism/sexism gets trumped by a 300-pound hungry alligator.