Discuss the below:
Q: Propose 4 key service difference that make the following airports land on either "Andy's favorite" or "Andy's most despised" airport list.
Andy's Favorites:
Singapore Changi (SIN)
Atlanta Hartsfield (ATL)
Amsterdam Schipol (AMS)
Tokyo Narita (NRT)
Andy's Despised:
Paris deGaulle (CDG)
London Heathrow (LHR)
New York JFK (JFK)
San Francisco International (SFO)