Lord of the Rings: Return of the King
Sean Astin's performance as Samwise in The Lord of the Rings: Return of the King was impressive. Playing the loyal friend to Frodo, he had the audience in tears on a number of occasions. As shown by the photo above, it looks like the actor went method. Even in-between takes, it looks like the actor has been crying on set. Or maybe he was choked up by the scene in question.
It is said that when Sean Astin tried out for the part of Samwise, he reenacted the scene where he'd have to cradle the unconscious Frodo, who had just be stung by Shelob. And now he is filming that very moment!