The list has quite a few names and some of them have to be common with others' list.

Starting from the least to most, here's

7. Ginny Weasley- Many of you might disagree with this but Ginny in the movies was annoying to me. She dated guys at random even though her heart was fixed for Harry. Also didn't show much of a personality.

6. Percy- Another Weasley brother who was a prefect and also helped the Dumbledore's Army get caught by Umbridge.

5. Dudley Dursley - I think this point doesn't need much explanation as he was a bully to Harry since their childhood like his parents.

4. Cho Chang- This girl was so indecisive and dependent that even Harry couldn't bear her for long. I guess having a sorry butt doesn't help all the time.

3. Lavendar- Ron Weasley's clingy girlfriend who gave him chapped lips is no new to hatred.

2. Rita Skeeter- The journalist who made up news in order to feed gossip to the public has such an annoying presence. She could hamper someone's privacy just to grab a burning headline.

1. Dolores Umbridge- The name that needs no introduction cause I believe everybody hates her at some point. Even though she has a thing for cats(just like me), that doesn't spare her from my list. She was a sadist who tortured kids at her best and could exploit her power to achieve what she desires.