I don't mind Ran, although she's not my favorite character. She constantly interrupts Conan's showdowns with Kid or deductions, but has taken down quite a few criminals to make up for it. I dislike her anime-generic gravity-defying hair, but her personality allows her to empathize woth even the culprit and she interacts well with other characters. The fact that she hasn't discovered Shinichi's identity, despite her suspicions, is due to Gosho's intention of revealing it to her at the end of the series, or returning him to normal without her ever knowing. She's an anime girl, and has been waiting for Shinichi forever, so yeah, she's gonna cry. I have several personal reasons not to hate her.
1) She's been faithfully waiting through everything, and although on occasion she's broken down, Ran has never betrayed Shinichi. When I think of her character, I realize that my bf being an hour away and not seeing him for 2 months is nothing compared to what others are going through.
2) Ran is Gosho's interpretation of the character, and though we are speaking of her as though she were alive, she is nothing but a manga/anime character. I only ever "Hate" a character if they are working against the 'hero' or hurting others. Ran is doing neither of those things.
3) She is taking care of Conan. She worries about him, protects him when he needs it, and is altogether his guardian. Without even knowing fully who he was, she took him in, and is a kindhearted, if overly sympathetic, person.