Haha Shinichi is going to end up with Ran.
Unless Ran dies. Which isn't possible. BUT I do have to agree that Ayumi is best ending up with Conan :V
Why?
It is not that I think Conan will end up with Ayumi, or Ran will not end up with Shinichi. I just feel that this is the best outcome. Ran should just find someone else that wouldn't make her cry all the time. I don't know why, but I find Ayumi much more brave and courageous than Ran. She would grow up into a much more loveable and mature and confident girl than Ran is. Shinichi doesn't really have a proper childhood like haibara. That's why I will fully support him growing up again with Ayumi and learn and fix all the problems with his personality. Just like how I would want for haibara to grow up again with my mitsu chan. If Haibara ended up with Conan and with their personalities, I'm afraid they might raise a twisted child if ever they have any... Family warmth is so important...
But best is still different from want. I dunno, just that the shinran scenes had moved my heart quite a number of times and so I support ShinRan.