My first time playing through At1 I got rather frustrated with Lyner. I mean, he's pretty oblivious a lot of the time, but he's also really caring and thoughtful.
When I played through Misha's path, I really came to understand her, and, likewise, when I played through Aurica's path I couldn't help but fall for her.
Sadly, because of the immense depth that is added to Lyner, Misha and Aurica, a lot of the other characters suffer in my mind as a result. I don't feel as though I know Jack, or, actually, Radolf is a really good example of this.
It's funny, given that I usually do not like the "villain" that the character who I left saying, "I want to learn more about that character" was Mir.
Ah... all the babbling and I still can only say, "I can't choose" >_<

Maybe if the poll was, "Which Observatory maintenance droid maid is your favorite?"
*nods* Meimei for sure!