Before I moved to Los Angeles, I asked a friend who preceded me here (and who happens to do a weekly radio show interpreting the place) for tips on how best to grasp the entirety of this enormous city. His snappy answer: "You've just got to get high on L.A." Har har — but I now realize he had a point: if you want to understand any one of humanity's vast modern metropolises, you must look at them from above.
Videos like these provide you that opportunity without even asking you to visit the cities in question, let alone step onto a helicopter about to fly over them. The Los Angeles aerial video at the top cuts between several different parts of town at several different times of day, so at least some of it will satisfy those who've adopted as there own the folkloric-sounding observation, variously credited, that Los Angeles is the most beautiful city in the world, provided you see it not just at a distance but at night.
For a high-altitude look at a more traditionally attractive metropolis, have a look at the aerial video of London. When a man is tired of looking at London from above, as Dr. Johnson might have said (had helicopters and motion pictures appeared in his lifetime), he is tired of life from above, put perhaps he can get a refresher by watching the flight over Tokyo just above.
In many ways, this aerial exploration of Seoul (actually an episode of 한늘에서 본 하반도, or The Korean Peninsula Seen from the Sky, a show aired in EBS, kind of the PBS of Korea) offers a view of a city that rolls some of the most striking large-scale features of Los Angeles, London, and Tokyo into one: a majestic river cuts through it, its stimulating built environment rises high and dense, and explosive 20th-century population growth has expanded it into an hypnotic sprawl.
Of course, all this only prepares you for the really interesting part of any of these cities: getting down there on foot and experiencing the details for yourself.