The moment of Ian's Heel-Face Turn. Throughout the entire movie, he's only been grudgingly complaint, respectful of the boys' mission but snarky nonetheless. Then he finds out he's going to be laid off and the station changed to easy listening. When the CPA that's been crawling around the air vents drops the MP5 that the nutty SWAT commander gave him, Ian uncertainly picks it up. Chaz sees him, grimaces, and slowly raises his hands, figuring it's over. Then Ian shakes his head and hands the gun over, joining their side.
The Lone Rangers tearing up their contract and trashing the stage (part of the contract being that they would lip-synch during concerts) when they realize that they are being signed based on the publicity from their stunt and not the quality of their music (the agent signing them hadn't even heard their demo and was banking on name recognition from all the press they were getting). Honor Before Reason on prime display.
The mild-mannered Police rookie Officer Wilson gets his badge defaced by a thug with a lot of tattoos and piercings. Officer Wilson responds by calmly ripping out the thug's nipple ring, causing the man to scream shrilly and drop to his knees in pain.