David without a doubt, because he was “a man after God's on own heart.”
And when he had removed him, he raised up unto them David to be their king; to whom also he gave testimony, and said, I have found David the son of Jesse, a man after mine own heart, which shall fulfil all my will. Of this man's seed hath God according to his promise raised unto Israel a Saviour, Jesus:
So,David was the greater king