I'm curious what model and configuration of the 747 has the most seating capacity actually used somewhere in the world. The Wikipedia page lists "typical" seating, maxing out at 467 (the 747-8). But that list also shows "Exit limits" on the 747-400 as 550 or 660 depending on exit type, and the 747-400 article claims the 747-400 can be configured in a single-class setup with 660 seats (matching that upper exit limit). The 747 article says:
In Japan, 747s on domestic routes were configured to carry nearly the maximum passenger capacity.
At the opposite end of the luxury spectrum is what All Nippon and Japan Airlines have done to a few of their 747-400s for high-density domestic routes in Japan.
They carry nearly 600 passengers in one class.
So, is the 660-seat 747-400 configuration actually used anywhere? Or if not, what's the largest actually used, and what model is it?