I will start of....
Ai/Shiho/Sherry - she´s cool, awesome, mysterious and she can screw so wonderfuly with Conan´s/Shinichi´s head you just have to love her. XD
Also i like that she´s a "grey" chara with doubt and guilt among all those "white" innocent and carefree or "black" evil and cruel charas.^^
As for Ran, she´s nice and cool too. It´s just a shame that the whole story seems to scream that she needs Shinichi to shine, Ai on the other hand can do that on her own.
as for others
Spoiler (mouse over to view)
Vermouth - she's cool don't want to spoiled what she does
and Masumi Sera - mysterious
and Masumi Sera - mysterious
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