So there's a joke about Applejack being a background pony that's been going around the fandom for some time now. Believe it or not, I understand why people feel this way. I don't agree with it, mind you, but I understand it. Applejack just doesn't scream "look at me" as loud as the rest of the Mane 6 do. Rainbow Dash has her boasting, Pinkie Pie does the most random things you ever saw, Rarity has a certain flair for dramatics, Fluttershy squees and talks to animals, and Twilight Sparkle is freaking princess for crying out loud. Mean while, Applejack is just there, quietly being awesome.
I won't lie to you, when I first started watching the show, Applejack wasn't my favorite pony, in fact she was near the bottom of my list. Watching the show for the first time, it was so much easier for my to pay attention to the plot and the "louder' characters. In fact, Applejack was still at the bottom of my list after I'd caught up on all episodes of Friendship is Magic, it wasn't until I started rewatching episodes that she began to stick out to me.
During that second watch through, I already new the plot and the resolution, so I was able to focus in on some of the minutia of the series. This is the stage where I truly fell in love with not just Applejack, but My Little Pony as a whole. There's a difference between shows you can enjoy the first time, and ones you can watch over and over and always catch something new; Friendship is Magic is one of the later; and when you rewatch the episodes, I highly recommend paying extra attention to Applejack.
As many of you know, a lot of what I love about Applejack is how much she reminds me of wife. They are two of the hardest working folks I know, they both have a country upbringing, and a strong devotion to their respective families. It was during the rewatching of Applebuck Season that it snapped in my head. When I saw how stubborn Applejack was in that episode; I knew she was not only my wife in pony form; but also best pony.
But you don't have to be in love with my wife to love Applejack. Applejack is honest and dependable. She is the hardest worker you'll ever see, and the best friend you'll ever have. Sure, she can be a bit blunt at times, but only because she tells it like it is. And you know what they say... "A true friend will always tell you the truth, even if it hurts." And trust me friend, I'm telling you the truth... Applejack is best pony!