Who's your favorite blue-haired girl?

According to otakus from Akihabara, the most popular anime girls with blue hair are:

7: Ika Musume (Shinryaku Ika Musume)


Technically not hair.

6: Erio Touwa (Denpa Onna to Seishun Otoko)


Our favorite cute cousin.

5: Konata Izumi (Lucky Star)


Everyone's favorite loli from 2007.

4: Ami Mizuno (Sailor Moon)


Most popular of the sailor senshi.

3: Nymph (Sora no Otoshimono)


I am not familiar with Sora no Otoshimono so no comment.

2: Sayaka Miki (Puella Magi Madoka Magica)


The least popular mahou shoujo.

1: Rei Ayanami (Neon Genesis Evangelion)


Everyone's favorite kuudere.

Honorable mentions:
Mio Nishizono (Little Busters)
Klan Klang (Macross Frontier)
Ami Kawashima (Toradora)
Sayaka Maizono (Danganronpa)
Aya Komichi (Kiniro Mosaic)
Mio Naganohara (Nichijou)
Umi Ryuuzaki (Magic Knight Rayearth)

Source (Japanese)