Dr Strangelove, where Peter Sellers confronts an Airforce officer and says "Listen Colonel Bat Guano, if that is your real name."
Also the scene where Captain Kong, as he falls with the nuke, makes out like he's bronco riding.
Also the Wizard of Oz scene, towards the end where the 'wizard' is exposed and says: "Pay no attention to the man behind the curtain . . ."
villabolo