Cho, Harry's first romantic love interest, messes up entirely in The Order Of The Phoenix when whatever little spark the two had between them completely fizzles out. From a wet kiss 'because she was crying' to an awkward tearoom spat in Hogsmede over Harry's friendship with Hermione, Cho messes up when she fails to see the real hero that Harry is and instead chooses to side with her friend who betrayed the D.A. While it's understandable that Cho has to choose between her alliances in order to keep people happy, her lack of conviction for Harry's point of view makes her a poor choice in the Potter Love Department. But Harry is her loss and Ginny's gain, as we find out in the last book.
I love Stephen King and music festivals; I eat my toast upside down; I daydream about getting married probably a bit too much; and I wish every day for a pet sausage dog puppy (who never materialises – sob).