Poll: Actress Oscar Winner for Playing Someone Mentally or Physically Disabled

Of these Oscar winners for Best Actress or Supporting Actress for the role, which actress that played a character that was severely mentally or physically handicapped or disabled do you think gave the best performance? Discuss here: http://www.imdb.com/board/bd0000088/flat/232284824 Note 1: This poll does not include roles where actors had a disease, such as Tom Hanks in Philadelphia. It also does not include roles where the actor suffers from drug or alcohol addiction. Note 2: Watch for the list of actors also. Note 3: The words used to describe the handicap or disability of the character are directly from this website. Whether or not they are "politically correct" is unimportant.