Is it just me or is Rainbow Dash the most popular favorite pony for new bronies, but then everyone hates her once they realize how much of a bitch she is?
"The Mysterious Mare Do Well" aside, I don't recall seeing her act like much of a bitch. I still enjoy her, but Fluttershy was always my favorite.
I still generally favor the entire cast though. Each character has something about them that I love,
except Rarity (I give her pity-love, but I still couldn't imagine the series without her). Strike that bit, there are a few things I enjoy about Rarity too.