DORY - who doesn't love "Finding Nemo"? I saw the movie opening weekend in June of '03 and I fell in love with Dory's "just keep swimming" optimistic attitude.
To me, her forgetful attitude came across as innocence. With her innocence came the ability to never be upset. She may not know you, but she always wanted to help. Even though she's a fish, I could tell she was always smiling... even when she was confused. Ultimately it was her perseverance that reunited Marlon and Nemo.
My child at heart quality is what makes Dory from "Finding Nemo" my favorite heroine.