Normally I would go Nibutani, but then this happened...
HNNNNNNNG.
I tend to like blondes more in anime than their brunette counterpart. The reason Nibutani was original my favorite lies with the fact that she had a very sweet and normal personality. Something about this show makes me wish for the one day that the protagonist ends with the normal girl (if it has been done, tell me I would love to watch/read).