The tanker hijacking. The tankers don't slow down after you massacre all of their vehicular support (and all the soldiers inside their transport), so you have to have your troopers leap off the helicopter on them and throw their drivers out. Depending on some random factor varying between playthroughs, they might shoot the drivers first.
Your player character gets knocked off the side of the San Fransisco bridge only to land on the undercarriage and proceed to fight your way up to the other side of the enemy lines and save the attacking force from sentry towers with machine guns.
Conner takes a flare onto the San Francisco Bridge and uses it to make a Heroic Sacrifice. He takes it out into the enemy columns, so the United States Air Force can target the Korean People's Army forces.
Even though some may not agree with me, the final confrontation with the enemy Goliath.