Actually, I thought he was pretty humorous here:
Harry Callahan: I know what you’re thinking. “Did he fire six shots or only five?” Well, to tell you the truth, in all this excitement I kind of lost track myself. But being as this is a .44 Magnum, the most powerful handgun in the world, and would blow your head clean off, you’ve got to ask yourself one question: Do I feel lucky? Well, do ya, punk?
Bank Robber: I gots to know.
He’s always played the straight man in comedy movies. Honestly I wouldn’t want him to try to pull off anything else.
Where is the humor in that?
I like the scene where the Chinese restaurant is being robbed by two semi-crazed gunmen and Callahan is just sitting there cool as a cucumber holding something in his hand. When one of the robbers finally notices him, the loon gives him a glassy-eyed menacing look. Callahan replies:
“You forgot your fortune cookie. It says you’re sh*t outta luck.”
Boom. He then kills them.