Which team's 1960s defensive line was called the "Fearsome Foursome"?

Which team's 1970s defense was known as the "Steel Curtain"? Which team's secondary was nicknamed the "Legion of Boom"? Which team's defensive line was known as the "Purple People Eaters"? Which team's 1970s defense was called the "Orange Crush"? Which team's early-1970s defense was known as the "No-Name Defense"? Which team's 1980s offensive line was nicknamed "The Hogs"? Which team's high-scoring offense around 2000 was called "The Greatest Show on Turf"? Which team's defense was known as the "Doomsday Defense"?