My favourite character to write was Raelynn in an Elder Scrolls roleplay, by far.

Raelynn, first and foremost, made me a stronger writer. She was perhaps entirely more flawed than she was good, I don't think she often did what a character "should" do, and in fact a lot of her actions and decisions ruined a lot of things. 

She had moments of great doubt, she was often ruled by spite and pride but every so often capable of showing incredible compassion, but only when she decided to give that. She was never talked into a decision. 

I loved exploring this beautiful, but completely tragic character.