Many of you already know that Applejack is my favorite of the Mane 6. I have said a lot of good things about her and even called her "Best Pony" a few times, but I haven't really explained in much detail why. Here are a few, not all, reasons why I love AJ as a character.
It's pretty much common knowledge in this fandom that AJ's parents are dead. Some fans have turned this into stories, comics, animations, etc. There have even been subtle hints of it in the show. I have done some thinking about what we know about the Mane 6's pasts, and I came to a conclusion that among them Applejack probably has the closest thing to a "dark" past (or a dark event in her past anyway).
I mean, think about it. Twilight was a prodigy in magic, a student of the princess, foalsitted by another princess, all topped off by nice (we can safely assume) parents and a brother she "never had a single fight" with. She may not have been too social, but she was hardly unhappy about it. Rainbow was also a prodigy in flying... and that's all we know. Fluttershy is more 50-50. She was bullied at a school she clearly didn't fit in, but on the family side, she seems fine. Pinkie's life was initially joyless, but again, she seems fine with her family. Rarity... we don't know too much about her past.
What we know about AJ's past (her parents died) seems much more... sad than the others, yet look how much it affects her today. Much like with Celestia, I really admire how upbeat and strong she can be despite her past. It would be really easy to let one event make you cynical or apathetic (like Moondancer or Starlight), yet Applejack (and Celestia) remains a helpful and positive pony. In fact, I would even say she became tougher because of that event. This, I think, is one of the greatest examples of Applejack's mental / emotional strength.
The not - stereotype
I've seen a lot of people label Applejack as a "southern stereotype", and I find that a bit unfair. The typical country bumpkin in media is usually unintelligent, lazy, and has very little to his / her character other than the accent and the country mannerisms. I don't think any of these descriptions fit Applejack.
First of all, Applejack is not dumb! So many people I've seen say that she is "less intelligent" than her friends or "the dumb muscle". I disagree. To paraphase Twilight in Read it and Weep, just because she's strong doesn't mean she isn't smart. I see Applejack as a pragmatist, and she has used her head quite a few times in the series. Bats, The Mane Attraction, and Somepony to Watch Over Me (only while fighting the chimera; the rest of the episode didn't make her look too intelligent) to name a few.
This should be obvious to anyone who watches the show, AJ isn't lazy either. In fact, one of her biggest character flaws is that she can be too much of a workaholic. Even more, her complete lack of laziness was highlighted in the fourth episode! I won't spend to much time here, because I'm only pointing out the obvious here.
Yet another common complaint for her character is that she's one note, so I'm going to address that because it ties in with the third trait of the typical southern stereotype. Here's the thing: I can see why someone would see Applejack as a country stereotype, much like how some might see Twilight as a typical nerd, or Rainbow Dash as a typical jock. However, those short phrases don't define any of those characters any more than "pony fan on the internet" defines me or any of you. Those are tiny portions of their characters. Can I name any traits of Applejack that don't relate to her being country? Yes, I can: she's honest, a family oriented pony, strong, mature, she cares about her friends, she can be stubborn sometimes, etc. See, she has traits outside the two or three tropes that people associate with her, same as any other character. This is why I don't see her as one note.
I think Applejack is the most mature of the Mane 6, and that's where a lot of her best character moments come from. In a quite colorful and quirky cast, there should always be at least one voice of reason to help keep friends in line and keep them from doing stuff they shouldn't. Applejack, and sometimes Twilight (when she's not going crazy herself), fits this role the best for the Mane 6.
One reason I love this aspect of her personality is comedy. In my opinion, AJ's funniest moments are when she plays the "straight mare" to a friend. One of the best examples of this would be Simple Ways. In that episode, Rarity was acting... irrational and AJ had to snap her out of it. It was hilarious! The way they played off one another, how AJ decided to fight fire with fire, AJ's patience with Rarity's antics, it was glorious to watch!
Even better than comedy is when her role as the voice of reason is taken seriously. In these moments, she shows her best qualities to help a friend who needs it. Example: Sisterhooves Social, the episode that made Applejack best pony. She may not be the central focus, but she still shines. She uses her maturity to help two individuals: Rarity and Sweetie Belle. I think it's worth noting that after her big argument with Rarity, Sweetie turns to Applejack and Apple Bloom, as if she knows how strong their sisterly dynamic is. Applejack behaves in a very sisterly and nurturing manner to Sweetie Belle. She listens to the filly's problems and empathises with her, assures her that Rarity will come around, and attempts to cheer her up by letting her participate in fun activities.
As for Rarity, I think watching the campfire and "apple pie" scene would be enough to show how she helps her. She isn't rude when calling out Rarity for her behavior. She doesn't say "you are a really selfish and bad sister and you should be more like me", she instead tries to appeal to her with a metaphor. She gives out the message that Rarity needs to think of Sweetie more while being careful not to hurt Rarity. She's being honest but not blunt, get what I mean?
Now, this is not about Applejack herself, but rather what others think of her in-universe and what that says about her. Applejack has a good reputation among Ponyville, and I personally think that says a lot about her. To explain this in more depth, I will look at two episodes where the town's positive view of her is most notable.
The first is Applebuck Season. Here, all of Ponyville, her friends included, are celebrating her abilities and accomplishments. Notice how all the things her friends need help with need her skills in some way. Rainbow needs her physical strength, Pinkie needs her cooking skills, and Fluttershy needs her herding skills. Of course they all fail because AJ was sleep deprived, but that's not the point. The point is that here, Ponyville likes AJ because of her skills and dependability.
The second episode, Leap of Faith, is a bit different. Here, it can all be summed up in one word: Trust. The ponies really trust AJ and what she says. If she says a product works, they'll buy it. While it is wrong to put that much weight in one person's words, I can understand why they would. This really shows how much of an impact Applejack's honesty has on those around her.
Is there any wonder she feels so much pressure when she thinks she has let them down?
Yeah, that's about it. I might add more though. For now, comment below on any additional reasons on why you think Applejack is awesome. I might even expand on that reason here. Or if you have anything you want to say against her or my opinion of her, please post that too! I'm open to discussion. (aj)