In rough order of visit:

1. Canada
2. Bermuda (1984)
3. United States
4. The Netherlands (1992, 2006, 2009)
5. Japan (2002, 2008)
6. Australia (2002, 2004)
7. Cuba (2005)
8. China (2006, 2008)
9. Denmark (2006)
10. Sweden (2006)
11. Belguim (2006, 2009)
12. Germany (2006)
13. Czech Republic (2006)
14. Austria (2006)
15. Switzerland (2006)
16. Lichtenstein (2006)
17. France (2006)
18. Monaco (2006)
19. Ireland (2006)
20. United Kingdom – England, Scotland, Wales (2006)
21. French Polynesia – Marquesis (Hiva Oa, Nuka Hiva, Haupatoni), Tuamotus (Apitaki), Societies (Tahiti, Moorea, Huahine, Raiatea, Taaha, Bora Bora) (2007)
22. Cook Islands – Rarotonga, Aitutaki, Palmerston (2007)
23. Independant Samoa (2007)
24. Kingdom of Tonga (2007)
25. Fiji (2007)
26. Vanuatu – Efete, Ambrym, Espiritu Santo (2007)
27. Solomon Islands – Guadalcanal, Marovo Lagoon, Ghizo (2007)
28. Papua New Guinea – New Britain, New Ireland, New Hannover, Duke of Yorks, Madang Provinces (2007-2008)
29. Feterated States of Micronesia – Chuuk (2008)
30. Guam (2008)
31. Okinawa (technically part of Japan but it is pretty much in its own world; 2008)
32. Midway Atoll (technically part of the US, but cool enough to be listed separate; 2008)
33. Kenya (2009)