| Great quiz, especially panamanama! In terms of other possibilities just did an excel sheet using wikipedia info looking for 2 letter combos not used in this quiz, came up with:
Chaddis Ababa, Nepalgiers, Portugalgiers, Senegalgiers, Burundili, Tongaborone, Lesothoniara, Saint Kitts and Nevislamabad, Sri Lankabul, Sri Lankathmandu, Sri Lankampala, Malibreville, Malilongwe, Malima, Malisbon, Surinamexico City, Surinamelekeok, Sierra Leonew Delhi, Ukrainew Delhi, San Marinouakchott, Andorrabat, Côte d'Ivoireykjavík, Singaporeykjavík, Montenegroseau, Montenegrome, Burkina Fasofia, Maltallinn, Maltashkent, Malawindhoek |