I want Ran to be with Shinichi for sure, but at the same time I don't want the ending to be a perfection. Something's probably going to happen between BO and Conan that even he couldn't handle and everybody thinks they are going to be doomed. And I also thinks that Ran will know about Shinichi's identity and it's just going to be a matter of time because I believe that every woman has a sense.
And maybe I said maybe Ran will make a decision that will be beyond our predictions. One of the possibilities is that she will know about the whole Conan thing and found out that there's no cure. Loving him so much she swallows the capsule and shrunk to Conan's size and be with him forever. This is plausible because if you like a person you will be sure of spending your life with him and it's a relatively happy ending like Gosho Sensei said. And plus repeating elementary and junior high does not seems to be a misery since Conan dealt with it just fine lol.
I always find Haibara being this seemingly hopeless and emotionless girl with a soft side. But it's less likely that she'll end up with Conan because I don't feel the vibe. Because if they were to be together and Gosho said he wrote the finale long time ago wouldn't he be laying the groundwork for their relationship? But the one who confessed in London wasn't haibara, and don't you think it won't be consider "happy" if Ai is to be with Shinichi? I mean Ran and Shinichi are the key couple throughout the theory and having Ai and Shinichi together is like you dated a person for a year and married someone else, it's not likely to happen and it's definitely conflicting.