Interesting statistics here.
http://www.citymayors.com/government/mergers_locgov.html
I do seem to remember that Jacksonville, Florida, was the largest city areawise (840 sq mi) with respect to land under political control.
Suburban or metropolitan areas are certainly larger.
I much prefer the European models.
I disagree somewhat that sprawl builds wealth. The value of something is somewhat arbitrary. Monetarily sprawl creates a concentration of wealth, but also higher cost for services, and inconvenience because of the population density. My personal experience is that the quality of life is better in Europe than the US, but they may be closer together these days.
Houston is one of the classic cases of mismanaged (laissez-faire) development. These days it seems to be competing with LA for the dirtiest, smelliest city.
As for Japanese suburbs, Tokyo and Osaka are surrounded by suburbs.
I personally prefer the countryside. Although I don't mind small cities, I don't particularly care for large cities like NY, LA, London, Tokyo, etc. On the other hand, I like most cities in continental Europe, and I really like Osaka.