I don't even know why, but Applejack randomly became my favourite a while ago. Before it was fluttershy. I guess applejack just seems the nicest to hang out with. Rarity might alienate you, RD would make you feel sort of loser-ish, fluttershy would be hard to hold a conversation with, twilight would overwhelm you with her books and nerdiness, and pinkie would overdose you on jitteriness. Applejack is caring, supportive, and stands up for people.