That's quite interesting. I never realised Tokyo was that heavily populated! I'd have thought the Indian and Chinese cities would have beat it, but then again, with China I think the population would be more spread out.
I would have thought London would be up there too, but on checking the later statistics we're about 7,556,900. So about 2 and a half million less than 'megacity (10 million) status' and a good deal less than all the cities listed.