The unhappy reality at the center of the political economy of Game of Thrones is one of particular interest in the Western world just now: that, as the proverb has it, great men seldom are good men, that the characteristics that make one an effective leader — a leader who is genuinely of use to his people — often are the characteristics that make one a god-awful human being. And the converse: that many of the virtues of good men make them poor leaders in difficult times. Jon Snow, who recently (and at the most inconvenient of times) has learned that he is presumably the legal heir to the Iron Throne, is a decent, fair-minded, liberal man — and an almost completely incompetent leader of men. His first real command (of the border patrol, essentially) ends with him being murdered by mutineers. (He is resurrected.) In trying to unite the kingdoms against the same threat that Sheriff Grimes et al. faced – zombies — he ends up getting romantically involved with the conquering Daenerys Targaryen, who believes herself to be entitled to sit on the throne. (She is also his aunt, but he did not know that when he first went to bed with her.) That romantic entanglement leads enemies and allies both to question his motives and calculations — and not without good reason.
Daenerys, on the other hand, is a power-mad megalomaniac — and, so far, a much more effective leader. She may be traveling the world freeing slaves, handing down rough justice, and building multinational coalitions for her own selfish reasons, but she understands her own reasons. She knows what she wants, and that she has to give the people she rules what they need if she is to achieve her own ambitions. This is not a matter of mere calculation: Like most successful megalomaniacs, she sincerely believes that her own destiny is fundamentally identified with the good of the people she rules and those she means to rule. She can be transactional when necessary, and will take good advice when she recognizes it, but she is a true believer, too: in herself.