Like i always say i'm going for ShinRan, actually CoAi doesn't make sense for me AT THIS MOMENT, It's true, Ai showed attraction for Conan, but now...i think she only sees him as a friend, and well, Conan obviously only thinks about her as a partner or a good friend xD...And ShinRan for me is the best option, considering that is canon, and the relationship had a development from the beggining, the only bad thing of it is Ran.
Yes, i'm ShinRan and i think that Ran is completely a Mary-Sue, at the beggining she HAD personality, but now sshe is something weird... a mix of a Mary-Sue and a tsundere...that's why i prefer Ai (L) But that doesn't mean i don't like Ran, i just think that she is getting moooore and mooore boring ....T.T(Have you seen the new OP? What in the ...? SHE WAS A PRINCESS X.X)