Odd answer, i suppose, but that's what it is. The show isn't what drew me to the show ( ). (Hence me still haven't finished watching the last half dozen episodes of s2). The show isn't the best show on earth or the next coming of Jesus, as some bronies declare. It's good, but nothing to lose your shit about.
It was the fan content. Specifically, music. I loooooooooooooooooooooove music. I watched an episode (specifically, the Zecora one), and was left extremely unimpressed about a show that teaches about political correctness and things so basic you'd have to be not even a little girl, but completely retarded not to understand.
If notacleverpony had not made "For the new Luna Republic", a piece with no words, yet one that almost made me cry, i would have never been a brony, likely. I discovered other content then. Fics... pics... etc. Watched the show, despite horribly cringing in many places.
And that's my story.