As for Ranko, I liked her more when there were only a few CGs.
For me it's the total opposite. I've been liking Ranko more and more as the roster grows... and especially since the anime lets me visually see her chuunibyou gestures.
Ranranko really hits all my otaku fetish buttons: gothic lolita fashion... anime albino (silver hair, pale skin, red eyes)... Yousei Teikoku-ish image song and stage outfits... awesome figure (considering her age, she'll probably fill out another 2 inches or so in the chest)... an empress of darkness and destruction...
Mai Waifu!
The only box Ranko didn't check off, was my thing for girls with "emo hair" that covers one or both eyes. There's certainly Koume, but there's something about her that just keeps me from fully activating Otaku Mode. Can't really put my finger on it...
However Fumika, despite lacking in the gothic department, kept appealing to me. Her quirky "quiet motor mouth" and sexy librarian traits pretty much sealed the deal.
Offhand I think Clarice and Yoshino Yorita have lots of
Mai Waifu potential for me, but they've yet to have Master CD's for me to make the final leap. There's also Shizuku Oikawa... because I like her... smile... yes...
most definitely her smile.
Chihaya wants her hair back. 
Chihaya would probably let her keep the hair, and just want some of that 77.
