Which city is known as "The Big Apple"?

Which city is known as "Motor City"? Which city is known as "The City of Brotherly Love"? Which city is known as "Music City"? Which city is known as "Sin City"? Which city is known as "Beantown"? Which city is known as "The Emerald City"? Which city is known as "The City of Angels"? Which city is known as "The Gateway to the West"?