I have not been to some of these, but this is my list of top places I want to visit (either first time or again):

NA: San Francisco, Boston, St Lucia (Caribbean)
SA: Rio, Easter Island, Buenos Aires
Europe: Venice, St Petersberg, Vienna
Africa: Casa Blanca, Victoria (Seychelles), Capetown
SWP: Vila (Vanuatu), Suva (Fiji), Noumea (New Calidonia)
Asia: Kuala Lumpur, Hong Kong, Singapore
Mid East: Gallipoli, Tripoli, Cairo