Jakarta 

I live in Jakarta, I'm not Indonesian and I am objective. 2010 census figure for Greater Jakarta (Jabodetabek or Jabotabek) is 26.6 million, larger than any other candidate except for Tokyo. A recent National Geographic Megacities episode described Jakarta as the 3rd largest megacity in the world. I am of the considered opinion that it is actually the second and larger than Seoul. Maybe it's time to acknowledge Jakarta. Its 100km long and 80km wide. Built up all the way.