Portrait of my wife
To me, a great portrait tells a story. It gives an honest glimpse into the person participating. It is also said that a photograph is a reflection of the photographer and how they see the world. The actual answer I am not sure, but a successful portrait makes me imagine something, whether real or perceived.
This portrait, to me, shows a strength, a quiet confidence and a willingness to see reality with all it's "flaws" while standing in the confidence of character. Imperfectly perfect.