I like the way he uses his power and position.
He's very well read, highly intelligent and has the most wonderful, dry sense of humor.
I also like the way he raised his sons, as a single father. He carried himself with dignity and poise, throughout all scandals around his marriage and affair with Camilla.
He is thrifty and careful with money.
He stands for tradition, natural conservation, history and cultural values, which are all dear to me.
I hated him for a while, when rumors about his liaison with Camilla emerged. I faulted him for Diana's unhappiness and the break up of their marriage. Later on, I realized he was a mere victim of the "system", trapped into marrying a woman he did not love while loving another one. And also, comparing Diana's demeanor after the divorce with Charles', I think he came way on top.
That kind of sums it up.