If I had to pick from the main cast (since they're the only characters I have even a basic knowledge of) i'd choose Rarity. Honestly I don't care much for the show myself, i've given it a chance here and there to see what all of the hullabaloo was about, but I just don't see it. All i've found was an ordinary (albeit girly) children's cartoon, which to be fair is about all I was expecting. And while I don't detest the show or anyone who watches it, I didn't find anything that stood out enough to me that would provide an explanation for the cult-like following it had and probably still has going for it.