At least 110:
New York (La Guardia)
New York (JFK)
Newark
Boston (Logan)
Dulles
Washington National
Miami
Orlando
Key West Naval Airfield (emergency landing)
Houston
Dallas-Ft. Worth
El Paso
Atlanta
Denver
Seattle
Gillette, Wyoming
Minneapolis
Little Rock
St. Louis
Phoenix
Chicago
Los Angeles
San Francisco
Redding, CA
Honolulu
Hilo, HI
Maui
San Juan, Puerto Rico
Antigua
Kingston, Jamaica
Nassau, Bahamas
Port-of-Spain, Trinidad
Mexico City
Veracruz, Mexico
Belize City
Guatemala City
Flores, Guatemala
Tegucigalpa, Honduras
La Ceiba, Honduras
San Pedro Sula, Honduras
San Salvador, El Salvador
Managua, Nicaragua
Panama City, Tocumen
Panama City, Paitilla
Panama City, Albrook
David, Panama
Changuinola, Panama
Bocas del Toro, Panama
El Real, Panama
La Palma, Panama
Sambu, Panama
Garachine, Panama
El Porvenir, Panama
Carti, Panama
Rio Sidra, Panama
Coiba Island, Panama
Contadora Island, Panama
San Jose Island, Panama
San Miguel, Panama
Jaque, Panama
Puerto Pina, Panama
Bogota, Colombia
Caracas, Venezuela
Ciudad Guayana, Venezuela
Quito, Ecuador
Lago Agrio, Ecuador
Lima, Peru
Cuzco, Peru
Arequipa, Peru
Nuevo Mundo, Peru
Sao Paulo, Brazil
Buenos Aires
Trelew, Argentina
Bariloche, Argentina
Iguacu, Argentina
London (Gatwick)
Paris (CDG)
Frankfurt
New Delhi
Bangalore, India
Nagpur, India
Bhopal, India
Lagos, Nigeria
Enugu, Nigeria
Old Calabar, Nigeria
Yaounde, Cameroon
Bamako, Mali
Libreville, Gabon
Gamba, Gabon
Rabi, Gabon
Nairobi, Kenya
Entebbe, Uganda
Mambasa, Zaire
Antananarivo, Madagascar
Diego Suarez, Madagascar
Cape Town, South Africa
Bloemfontein, South Africa
Durban, South Africa
Papeete, Tahiti
Nandi, Fiji
Sydney, Australia
Alice Springs, Australia
Mt. Isa, Australia
Wellington, New Zealand
Auckland, New Zealand
Christchurch, New Zealand
Dunedin, New Zealand
Invercargill, New Zealand
Napier, New Zealand
Milford Sound, New Zealand
I’m sure I’m forgetting some brief stopovers. I’m also not counting a few small airstrips where I’ve landed by helicopter, since there was no real airport there.