Arthur C. Clarke's Childhood's End is $1.99 at Amazon. The origin of the giant spaceships appear over Earth's major cities trope that V and Independence Day copied.
In the near future, enormous silver spaceships appear without warning over mankind's largest cities. They belong to the Overlords, an alien race far superior to humanity in technological development-and their purpose is to dominate the Earth. Their demands, however, are surprisingly beneficial-end war, poverty, and cruelty. Their presence, rather than signaling the end of humanity, ushers in a golden age-or so it seems.
I wasn't fast enough! Sale expired. Sorry folks!