Also Atlanta.
I can't really judge many other BIG airports because I haven't been to them in a very long time.
LAX was just filthy, last time I was there. Also, back in... ummmm, 2009 or so I went to Japan to visit my son. We left Japan, Tokyo, one the cleanest airports in the world I suspect... AND, the most courteous people working there you can imagine... flew to LAX with a LOT of non-English speaking Japanese tourists got off the plane with my wife and I. My wife and I were humiliated.
You would have thought the Japanese tourists were ISIS recruits the way they were treated by the LAX folk. Cursing, shouting, giving them the finger.... it was shameful. - JamesJM
