I hear Rarity crying again in my mind...
I haven't voted yet, but I can see and understand why everyone has voted Rarity.
She has done some pretty generous stuff before, making everypony special team vests for Winter Wrap Up, was the first to to urge Twilight to find a spell and first to subject herself to the trial of said spell to go aid in the cheering line up for Rainbow Dash. Made everypony multiple outfits, and ofcourse shared her tail with the serpent.
However, a lot of things she did were means to forward her own ends, and has given others impressions of her self centered ways.
She has demonstrated this on various levels in multiple episodes.
My first impression of her when I first saw her, was "Prissy" and I wouldn't have known her for her entitled element.
She is one of my favored ponies in the series, and all of the mane 6 practically hold true to their elements, but I'm afraid, I too, would have to vote on Rarity.
Now, this doesn't mean my view of her has changed, as I feel, she has yet to reveal a true mark of generosity in the near future, and will possibly outshine and surprise all.