To be honest, Baron Vladimir Harkonnen was much more intelligent and less creepy in the books than in the movie. A lot of fans would agree. But then, although I read all the books, I didn’t really like them too much.
I know a lot of true fans hated the Lynch film. I became a fan because of the film. I figure if you’re going to do a memorable villain, make him as outrageous as you can. McMillan’s Baron was deranged and scary. The later miniseries remake with some corpulent English actor was so bland as to be utterly forgettable.