Draco counts. He was a jerk the entire series and was a Death Eater the last two books. Just because he kind of turned good at the end doesn't somehow automatically classify him a hero.
I picked Barty- but I can appreciate that someone could pick Umbridge- she is written extremely well as a villian- frequently drawing more hate than Voldy. Her ability to be a villian by using 'the rules' and being untouchable is super frustrating.