Check out Willis in In Country and Nobody's Fool. The guy has some serious chops, but he sleepwalks through crap like Armageddon to support a lifestyle.
Oh I give him plenty of acting credit.
Here's Willis in an '88 Playboy interview excerpt on both Nicholson and DeNiro:
PLAYBOY: What movie actors do you model yourself after?
WILLIS: Al Pacino and Robert De Niro-the less-is-more school, the behavior as opposed to the presentation of the work. Dog Day Afternoon was an amazing film. Scar face was a brilliant movie, one of Pacino's best. De Niro in The Deer Hunter; there's a scene where they are up in the mountains and he holds up this fucking shell and says, "Hey this is this, ain't nothin' else.
From now on, you're on your own." It was mystical to me. I wanted to know that guy with that line. His work continually amazes me, how hard he strives to create a living, breathing person in each role. I would like to be directed by him. And Jack Nicholson is enormous. I would like to play a part of the same stature as the one he played as Eugene O'Neill in Reds. I think Sean Penn's work is really honest, and he strives not to repeat himself. I like actors who don't always make safe choices. Bill Hurt is a great example, and he pulls it off. Robert Duvall. Meryl Streep is the greatest living actor that America has, man or woman. Her stuff exemplifies what's important to me in acting.