Hopper always impressed me as being just on the edge of a violent breakdown. I can’t think of a role I have seen him in that wasn’t interesting and, usually, entertaining (when not downright disturbing). I suspect he is the kind of actor that some prefer not to appear with because even when saying nothing he draws attention like a magnet and dominates his scenes. There have been others like that (Strother Martin comes to mind) and they are among the best.