On leaving the plane I always thank the pilot for the landing.
Know what a good landing is? One you can walk away from
Know what a great landing is? One where the plane can actually fly again.
I remember my dad telling me about holding short of another taxiway at Narita and watching another plane coming in to land. I don't remember what the equipment was, but it landed so hard that there was fuel leaking out of the wings.

Not cool. lol