Define "efficient". I define efficiency as the config that handles that airport's traffic with the greatest possible expeditiousness. Given that, any airport with a good traffic management plan and a single runway close to the terminal(s) would qualify as "most efficient". Something like FUK
in Japan, which handles a huge amount of traffic given that it only has one runway. I highly doubt somewhere like DEN
handles more passengers per runway, or even has fewer delays or shorter taxi times.
I'm tired of being a wanna-be league bowler. I wanna be a league bowler!