1. Applejack
She's a great character; I enjoy her bluntness and how down-to-earth she is. Her accent isn't too overdone either, something which most other shows tend to do with Texans. I can actually understand her! :D
2. Octavia
I know, I know. She's just a background pony, why's she so high? I like the way the fans adapt her personality, and the cello's a nice instrument. She seems pretty interesting, plus her design is cool.
3. Celestia
I like her colors. Luna's cool, but I prefer her sister better. She has an air of kindness to her, and I wish she was more popular. Her personality could be expanded on a whole lot, and I long to see play a more major part in the show. (Right now she's just "that one ruler who we don't really care much about.")
4. Lyra
... Yeah, another background pony. I think of her as cheerful, yet sophisticated, a nice yet uncommon match. Generally if someone's fancy, it's assumed that "Okay, they hate fun."
5. Sweetie Belle
Sweetie's the most amusing filly in the show. I like her relationship with Rarity, and her singing's pretty neat too. She reminds me of Bubbles from PPG.
6. Zecora
Her rhyming is fascinating, and it's interesting how she manages to live in the Everfree Forest. I wish she appeared more often in the show, and even in fanfiction.
7. Chrysalis
She's an interesting character, and I find her species cool. Yeah, evil and not exactly the most original thing, but still cool.
8. Fleur De Lis
I like pastel, light colour schemes, and that's just what hers is. Her poses can get tiring, but overall she acts well.