Agree, there are three actors who are 180 degrees opposite of sane. They are Mr. Woods, Mr. Walken and Mr. Hooper. In fact, one of the greatest face off scenes I've ever seen was between Christopher Walken and Dennis Hooper in "True Romance". This scene is closely followed by Deniro/Pacino in "Heat" and Deniro/Walken (Russian roulette scene) in "The Deer Hunter".
"Heat" was such a great movie, I'll never understand why it's not more widely known. Most movie fans I talk to have never even heard of it.