There's already a thread like this but whatever.
1. Makoto - For some reason, I like tomboys because I tend to like tomboyish stuff (video games) and I can understand her becoming a bit more feminine. Plus, she's has the best singing voice. Guess my childhood influenced me to like her more than anyone else.
2. Takane - Her personality is strange yet amusing. Puchimas! Takane is an icing on a cake.

Oh, and lovely voice, too.
3. Yukiho - While the shy archetypes are kind of a hit-or-miss, Yukiho's a hit for me. Nice voice and "First Step" is beautiful. Kinda doesn't help that I support Makoto/Yukiho (
platonic) pairing. They just go so well together.
4. Azusa - Very pleasant person with a pretty voice. Kinda wish that Namco do a better job of making cuter songs for her because they don't appealed me right now.
5. Hibiki - Has a likable personality and has a lovely singing voice.
6. Ritsuko - Mostly liked the Puchimas! version. Again, voice varies on certain songs.
7. Haruka - Not much to say about her. Voice varies on certain songs.
8. Mami - Liked her hairstyle and mature personality more.
9. Ami - Not much to say about the twins. They're funny, but they have lackluster singing voice.
10. Chihaya - I never get why people liked her. Her voice, while powerful, sounds very strained (Ohayou! Asagohan, Chiisaki Mono cover *coughs*). She also has the most boring storyline out of the girls. It's always the dead brother in a car accident, her parents divorcing, and her feeling depressed about it (and trust me, it gets old fast). I'm also getting sick of her ALWAYS getting slower songs and that's the reason why I liked to see her singing songs like "Just be myself!!" and "choco fondue". I think she sounds better on lighthearted songs overall.
11. Yayoi - Cute, but overall indifferent. Her voice is grating though.
12. Miki - Very obnoxious in personality and voice (unless she sings deeper or softer songs).
13. Iori - Never cared for Tsunderes. I think they're one of the worst archetypes ever.