Paris Charles de Gaulle, France
Why ? CDG is on the verge of becoming the worst airport simply because it is suppose to be a first class airport worthy of a first class city. Instead, even third world nations would reject it. The citizens of France are astonished and ashamed of its poor state. Reasons : dirty, ugly, rude staff, inconvenient, expensive food, plastic seating with armrests, steal benches, noise, mean security, high air-conditioning, homeless people, "What a dump", dogs piss and shit on the floor.