In my opinion, these are my worst picks for shoujo manga. All the manga on this list are series I have finished or are close to finishing.
I think Black Butler is classified as shounen, so that's why it's on this list. These are series that I have either finished or read enough of to rate. These are all just my opinion.
All these are manga I have finished, or have read enough of, to believe they are great series. This is just my opinion :)