He sent, and brought him in. Now he was ruddy, and withal of a beautiful face, and goodly to look on. Yahweh said, Arise, anoint him; for this is he.
Actually, David had a great admiration for Saul. Of course just a young boy, and he was at that hero age, and Saul, big, tall, handsome fellow became sort of a hero in David's eyes. David always respected Saul right to his death and even after his death. David never lost his respect for this man.