And ATL,ORD and LAX aren't international airports?
Besides, you are ordering by passenger count, which is a perfectly fine way to "rank" things in many ways. More appropriate for the pilot and ATCOs is the number of operations. Problem with this measure is it only counts airports that have control towers to control aircraft ops. I've got to believe there are some untowered airports that have more operations, even if it is "only" C-150's doing touch and gos.