Blue Heelers/Awesome

Special mention has to go to Superintendant Clive Adamson. In his sixties and uncouth for his rank, he is part of the takedown of a group of gunmen. The group, a woman in particular, is considered particularly scary, and had already broken out from prison. After the shootout involving a speeding vehicle, a machine gun fired on the police and a shotgun used to take out the engine, Clive flattens he flattens the biggest of the gunmen when he breaks from the group of younger officers trying to restrain him.
Nick gets a memorable one where he recounts trying to save a little girl during a flood. Told mostly in black & white, Nick swings from emotionally saying how he tried to anger that he couldn't save her to rage at Adam because he thought he'd abandoned them.
When Nick returns to the show as a detective he is quietly threatening a suspect in the station bombing. Nick then roars in his face, scaring him so bad he pisses himself.