1) The music. I suppose someone like you wouldn't have heard of Tenmon.
2) I happen to like the LOL SHAFT style - there were several very good visual metaphors there, too.
3) It was very well paced compared to other shows in it's genre, having everything intertwining as opposed to glasses girl route then sickly girl 1 route then boisterous girl route etc etc.
4) The drama was done well by anime standards, although I suppose you'll respond to that with nothing but a "Ha ha oh wow."
5) Everything was concluded without resorting to an unexplained miracle.