Rainbow Dash is a bratty, obnoxious, immature bully. She is a she-jock. I REALLY hate her.
The way she mocks her friends, the way she terrorized her potential pets in season two (that, in itself, I find completely unforgivable.) And she is pig-ignorant. She is a self-centered nag.
Applejack is a cool, collected mare with her hooves planted firmly on the ground. She is selfless and honourable, takes humble pride in her hard-working cowgirl life, and is really sweet in appearance. The way she wears her mane and tail, her cute freckles, her cute cutie mark and those apple green eyes... And the hat just nails it.