Dan Brown without a doubt. You know an author is controversial when the Catholic church wants to boycott their novel and other authors take turns to insult it. Brown is not a spectacular writer, but he knows how to tells an interesting story that keeps reader turning the pages. I know a lot of critics felt that The Da Vinci Code was a terrible novel, but nobody can dispute what a cultural phenomena it became. As an aspiring writer myself it gives me hope that I could one day write something that will entertain people that much. Personally, I find the stuff written by Brown to be much more entertaining than say the massive books written by so called "masters" that are barely readable.