I don't know if I would say Moriarty is the best villain storywise, but he is one of my favorites. His intelligence, style, and humor create the best crime puzzles for Sherlock Holmes to solve. The connection between this villain and "hero" draw me in and change the feel of horrible crimes to seeming like a best friends quarrel. They are dorky and make me laugh in all the wrong situations. While I know Moriarty is terrible, I can't help but love his work.