JT Walsh, in just about anything, but especially in "Backdraft" and "A Few Good Men".
He was also excellent as John Ehrlichman in "Nixon" opposite James Woods & Anthony Hopkins.
Not sure if he was mentioned, but John Spencer was a great character actor IMO. He was most famous as Leo McGarry on "West Wing," but was also in "LA Law," "The Negotiator," "Hoffa," and "Cop Land."
