7. Clara Oswald
Clara is the Eleventh Doctor's "Impossible Girl," having met him throughout his time stream as different incarnations of herself. She exists as a character outside this mystery and calls the Doctor out on him trying to compare her to others telling him, “I'm not a bargain basement stand-in for someone else." She sticks by the Doctor and reminds him of the good qualities he possesses. She has been a companion for only the second half of Season 7 and 2 specials so far. When series 8 begins, she will be going on adventures with the newly regenerated Twelfth Doctor.