I did some research and found some names of potential wonders. I tried to conciliate monuments from all over the world, of all eras, and of the most varied types: temple, cathedral, theater, palace, statue, castle, tomb, skyscraper, tower, pyramid, museum, library... I know that some are not so wonderful or iconics, and others are not so visually unique, most of the good names have already been included in the game or in the first round, and when looking for monuments everywhere, some are really difficult. But let's go:
Asia (10)
Buddhas of Bamiyan (Afghanistan)
Burj Al Arab (United Arab Emirates)
Chogha Zanbil (Ancient Elamite, current Iran) - A Ziggurat as a wonder, why not?
Gyeongbokgung (South Korea)
Humayun's Tomb (India) - This is an important and impressive building history of Delhi. It is about a tomb of the Mughal emperor Humayun, who also comprises other subsequent Mughals.
Kandariya Mahadeva (India) - It's a Hindu temple and it is considered one of the best temples preserved from the medieval era in India.
Kinkaku-ji (Japan) - Or as it is best known: 'Temple of the Golden Pavilion'.
Marina Bay Sands (Singapore) - I think this very impressive, and worthy of being included as a game-ending wonder.
Prambanan (Indonesia) - It is a complex of Hindu temples. Perhaps the second most famous structure in Indonesia, behind only the Borobudur. I must say that this is as interesting as.
Temple of Heaven (China)
Europe (10)
Belem Tower (Portugal)
Belvedere Palace (Austria) - Very Beautiful
Bran Castle (Romania) - Beautiful, famous and with lots of history. Dracula's Castle
El Escorial (Spain) - One of the best names for Spanish wonders.
Kronborg (Denmark) - Very Beautiful, great option for a Danish wonder.
Palais des Papes (France) - This is very very impressive. One of the largest Gothic buildings in the Middle Ages. In addition, this has much history, being pontifical residence and the seat of Western Christianity during the century XIV. Reading about it, I wonder how Firaxis has not yet included it in the game as a wonder.
Santa Maria del Fiore (Italy)
Rijksmuseum (Netherlands) - The best name to think of in Dutch wonder, in my opinion.
Roman Forum (Ancient Rome)
Windsor Castle (England)
Africa (7)
Cairo Citadel (Egypt) - An Islamic wonder built by Saladin in his capital.
Colossi of Memnon (Egypt) - Two large stone statues of the Pharaoh Amenhotep III.
Fasil Ghebbi (Ethiopia) - This is a fortress-city in Ethiopia. It seems to be interesting, and I do not mind having cities as wonders.
Hassan Tower (Marocco)
Luxor Temple (Egypt)
Mortuary Temple of Hatshepsut (Egypt) - It is an ancient funerary shrine dedicated to the Pharaoh Hatshepsut
Royal Mausoleum of Mauretania (Algeria) - A great tomb of a king and a queen Berbers
North America (8)
Centre Block (Canada) - This seems me as a very beautiful building.
Chrysler Building (USA)
Cliff Palace (Pueblo, USA) - A good choice for a Pre-Columbian wonder of North America.
Library of Congress (USA) - The largest library in the world. I do not mind having two libraries, since they are from different eras.
Royal Palace of Palenque (Ancient Maya, current Mexico) - It seems very interesting, a great example of Mayan architecture. This palace was royal residence of Palenque's rulers, in addition to being the largest construction in the city. A different choice for Mesoamerican wonders other than Pyramids.
Palacio de Bellas Artes (Mexico)
Pyramid of the Niches (Ancient Maya, current Mexico)
Rushmore Mount (USA) - I know we've had this before, but not as wonder of the world.
South America (6)
Basílica de Aparecida (Brazil) - It is the second largest church in the world, after St. Peter's Basilica. Perhaps the most important place of Brazilian Catholicism, receiving 12 million pilgrims a year. This can fit in as a great wonder of end game.
Catedral de Brasília (Brazil) - This Cathedral is a masterpiece of modern religious art in Brasilia. It has a distinctive and impressive design. Very beautiful to appreciate.
Coricancha (Inca, current Peru) - The most important temple in the Inca Empire.
Santuario de Las Lajas (Colombia)
Teatro Amazonas (Brazil) - I know there are more imposing theaters, but this is a "jewel" in the heart of the Amazon rainforest, the first monument when one thinks of a structure of this region. It is the most significant expression of the richness of the rubber cycle in the Amazon.
Teatro Colón (Argentina) - It is acoustically considered one of the five best theaters in the world and also ranked as the third best opera house in the world, reaching a period of huge international success. It is very beautiful and the best name to think of an Argentine wonder.
Oceania (1)
Royal Exhibition Building (Australia) - Sorry, I could not find many names for potential Oceania wonders. However, this edifice seems to me to be very beautiful and interesting. This is Australia's first building to be awarded the UNESCO World Heritage status.
By Eras:
Ancient Era
Chogha Zanbil
Colossi of Memnon
Luxor Temple
Mortuary Temple of Hatshepsut
Classical Era
Buddhas of Bamiyan
Pyramid of the Niches
Roman Forum
Royal Mausoleum of Mauretania
Royal Palace of Palenque
Medieval Era
Bran Castle
Cairo Citadel
Cliff Palace
Gyeongbokgung
Hassan Tower
Kandariya Mahadeva
Kinkaku-ji
Palais des Papes
Prambanan
Windsor Castle
Renaissance Era
Belem Tower
Coricancha
El Escorial
Humayun's Tomb
Kronborg
Santa Maria del Fiore
Temple of Heaven
Industrial Era
Belvedere Palace
Fasil Ghebbi
Library of Congress
Rijksmuseum
Royal Exhibition Building
Teatro Amazonas
Modern Era
Centre Block
Chrysler Building
Palacio de Bellas Artes
Santuario de Las Lajas
Teatro Colón
Atomic Era
Basílica de Aparecida
Catedral de Brasília
Rushmore Mount
Information Era
Burj Al Arab
Marina Bay Sands