Which of these leaders do you think best represents the ideas of the Enlightenment?

None of them honestly. The "Enlightenment" really was anti-monarchy if you study it. It was fashionable for leaders of the Era, Catherine the Great as an example, to publically embrace the "Enlightenment", yet use that propoganda to consolidate there power. Catherine had Voltaire (a popular Enlightenment author) come and stay with her at her palace. They threw extravagant parties with the elite who supposidly embraced the enlightenment. Yet, she never freed the surfs, created a democratic legislation in Russia, or publically execute any other of the key political ideas of the Enlightenment. As I said earlier, it was fashionable for rulers to publically embrace it, but most did little to further it or put the idea of the Enlightenment into practice, thus, I feel they are all horrible "representatives" of the Enlightenment. Somone like Voltaire, who is not a politician or leader at all, represents it much better.