I have always thought the journey more important than the destination so I have flown over a lot more countries than I have visited. But to add my little list: Canada, Mexico, Bahamas, Puerto Rico, USVI, Grand Cayman, Jamaica, St. Martin, Denmark, Greenland (part of Denmark but unique), Scotland, Ireland, Wales, England (all part of the UK but also unique each), Iceland, France, Germany, Belgium, Switzerland, Italy, Crete, Corsica, Egypt, Bahrain, Pakistan, India, Thailand, Kuala Lumpur, Brunei, China, New Zealand, and Australia. I would have stopped in Saudi Arabia and a few other countries but they would not give me landing permission.
As you can see, South America and Central America are mostly or entirely left out. Some day....
Best regards,
RA1