In a recent interview, JK Rowling admitted that she wished that Harry and Hermoine get together instead of Ron and Hermoine.
To which I say...DUH.
It wasn't just the movies and the chemistry of Dan Radcliffe and Emma Watson but also while reading Joanne's writing, you just see that they both have more chemistry than Ron and Hermoine could ever have.
I could clearly see Ron having a thing for her and a love growing within but I never could never see him truly making her happy. Even while reading the later books, Ron and Hermoine's relationship felt forced and horseshoed into the series at the last minute.
Oh well, live and learn.