Which cities are MEGACITIES?

Which cities in the world deserve to be called megacities in Your opinion?

One common definition is that megacity is a city with population over 10 million. If so the following would be megacities according to citypopulation.de (metropolitan areas included):

Name English Name Country Population Remarks
1 Tōkyō Tokyo Japan 34,100,000 incl. Yokohama, Kawasaki
2 Ciudad de México Mexico City Mexico 22,650,000 incl. Nezahualcóyotl, Ecatepec, Naucalpan
3 Seoul (Sŏul) Seoul South Korea 22,250,000 incl. Bucheon, Goyang, Incheon, Seongnam, Suweon
4 New York New York USA 21,850,000 incl. Newark, Paterson
5 São Paulo Sao Paulo Brazil 20,200,000 incl. Guarulhos
6 Mumbai Bombay India 19,700,000 incl. Kalyan, Thane, Ulhasnagar
7 Delhi Delhi India 19,500,000 incl. Faridabad, Ghaziabad
8 Los Angeles Los Angeles USA 17,950,000 incl. Riverside, Anaheim
9 Shanghai Shanghai China 17,900,000
10 Jakarta Jakarta Indonesia 17,150,000 incl. Bekasi, Bogor, Depok, Tangerang
11 Ōsaka Osaka Japan 16,800,000 incl. Kobe, Kyoto
12 Kolkata Calcutta India 15,550,000 incl. Haora
13 Al-Qāhirah Cairo Egypt 15,450,000 incl. Al-Jizah, Shubra al-Khaymah
14 Manila Manila Philippines 14,850,000 incl. Kalookan, Quezon City
15 Karāchi Karachi Pakistan 14,100,000
16 Moskva Moscow Russia 13,750,000
17 Buenos Aires Buenos Aires Argentina 13,400,000 incl. San Justo, La Plata
18 Dhaka Dacca Bangladesh 13,100,000
19 Rio de Janeiro Rio de Janeiro Brazil 12,100,000 incl. Nova Iguaçu, São Gonçalo
20 Beijing Beijing China 11,950,000
21 London London Great Britain and Northern Ireland 11,950,000
22 Tehrān Tehran Iran 11,800,000 incl. Karaj
23 İstanbul Istanbul Turkey 11,400,000
24 Lagos Lagos Nigeria 11,000,000
25 Shenzhen Shenzhen China 10,450,000

And this is the list by UN statistical division (urban areas included):

Tokyo Japan 35,0
Mexico City Mexico 18,7
New York United States of America 18,3
São Paulo Brazil 17,9
Mumbai (Bombay) India 17,4
Delhi India 14,1
Calcutta India 13,8
Buenos Aires Argentina 13,0
Shanghai China 12,8
Jakarta Indonesia 12,3
Los Angeles United States of America 12,0
Dhaka Bangladesh 11,6
Osaka-Kobe Japan 11,2
Rio de Janeiro Brazil 11,2
Karachi Pakistan 11,1
Beijing China 10,8
Cairo Egypt 10,8
Moscow Russian Federation 10,5
Metro Manila Philippines 10,4
Lagos Nigeria 10,1

Would You agree wth this list? Do You thnk cities from least developed countries as Dacca and Lagos, being mostly slums without developed urban facilities should be in it. Or would You rather place there more developed world cities like Paris, London and Chicago, even if they do not fullfill the population criteria?>