The transformation in American Werewolf In London is tops in my book. They could have used primitive 1980's computer technology and made it look corny as hell like CGI does with every movie today, but they played it smart and shot it as real as possible, short of filming an actual werewolf. The transformation looks painful, too, which you would expect as your body contorts into the shape of a dog, right? So well done. And the rest of the movie was just as great. Awesome story, awesome effects, great music score. What a classic film.