Mine is a tie between Twilight, Rarity and Luna. Mush them all together and you get me I voted for Rarity though. Yeah, she can be a bit of a high maintenance, self centered drama queen but everyone is at some point, but making stuff for her friends for free, taking care of herself when no one believes in her, working hard to get to her dream even when she gets knocked down, supporting her friends even when she wants their success (Green isn't your color) is something I admire. And she's funny. To me.
And Twilight, I love her initial anit socialness, bookiness and obsessiveness. Lesson Zero was me to a tee.