Worst...I had the misfortune of being ill while awaiting a delayed departure at Nairobi's Kenyatta airport...oh, and there was an electrical problem so no AC and only emergency lighting. Lovely.
Best....I like the new terminal at SXM...and the boat to Anguilla is still right across the road.
Copenhagen, Kastrup, I've spent days there overall, most recently 8-9 hours a week ago. Its a really nice open, user-friendly airport with lots of things to do