I'm always amazed when non-Muslims have great things to say about Islam and our beloved Prophet Muhammad (SAW). Here are a few notable quotes from non-Muslims:

"if there is much misunderstanding in the West about the nature of Islam, there is also much ignorance about the debt our own culture and civilisation owe to the Islamic world. It is a failure which stems, I think, from the straitjacket of history which we have inherited. The medieval Islamic world, from Central Asia to the shores of the Atlantic, was a world where scholars and men of learning flourished. But because we have tended to see Islam as the enemy of the West, as an alien culture, society and system of belief, we have tended to ignore or erase its great relevance to our own history."

-Prince Charles, given at a speech at the Islamic Centre in Oxford

"If a man like Muhamed were to assume the dictatorship of the modern world, he would succeed in solving its problems that would bring it the much needed peace and happiness."

-George Bernard Shaw

""He was Caesar and Pope in one; but he was Pope without Pope's
pretensions, Caesar without the legions of Caesar: without a
standing army, without a bodyguard, without a palace, without
a fixed revenue. If ever any man had the right to say that he
ruled by the right divine, it was Mohammad, for he had all the
power without its instruments and without its supports."

-Bosworth Smith

Feel free to share others you have found.