Watching the series again, and nothing's changed. Akari is still my favorite, while Chinatsu remains as the only character I dislike. Chinatsu wouldn't even make it onto the bottom of a "like" scale; she's just too mean spirited.
Sakurako for me. She's totally cute. Her screaming 'Baka!Baka!' is the best. I am glad we got to see more of her in season 2.
Ayano is close second, got to love tsundere.
Kyoko and Yui tied for the third place.
For me it's Kyoko. I love her character (in fact for some could be a little annoying, but I don't see that in this way) and I've weakness for blonde girls, so my choise is obvious. Her sweetness and pervert side caught me~