Probably just comparing to anything else in Australia. But if you want wavy roofs, try Ashgabat, Turkmenistan and its falcon ...
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Also my affection for MAD (specifically T4) isn't because of the wavy roof.
It's because of many factors, including:
(1) the use of bamboo slats in the ceiling to give warmth and texture to the vast interior;
(2) the use of uplighting which highlights the warmth of the bamboo ceiling and spreads it throughout the terminal;
(3) the massive sunlights which bring daylight inside;
(4) the use of lightwells to distribute the sunlight throughout the building, even on lower floors;
(5) the subtle use of a rainbow of colour on the supporting structures to help PAX navigate the terminal; and
(6) the visibility of this rainbow effect from outside, even from the windows of aircraft as you taxi to the gate, which is very familiar and welcoming.
These have been recognised by various awards.
They stand in contrast to the square block steel and glass structure that is WSI: Sydney basin limestone panels notwithstanding.