Who should I go as to a Harry Potter party?

I've go black hair (just lower than my shoulder and wavy) and very tanned skin. I need some suggestions of who I should go as. Please don't say Parvati or Padma Patil. I do have the right things to go as Hermione but I don't look like her. I want to go as a girl (duh) and look good. I'd also like to be a proper character. Thanks!