I live in London, UK, but I'm original from Bilbao, Spain. I'm moving to Tokyo, Japan, in 6 months.
The weather in London is terrible, you barely see the sun. Doesn't rain as much as they say though. Here I'd say about 40-50% of the people are British. Less so in the centre than in the suburbs. About 10m people in the metropolitan area.
The weather in Bilbao is somewhat better, but it rains much more often than in London (3-4 times a week). However, when it's not raining you also have sunny days which you rarely have in London. The weather is warmer also, and you can actually go to the beach in summer time. Though winter time is colder and we have quite a bit of snow. Not so cosmopolitan, about 1m people and 12% foreigners, mostly from South America and North Africa.
Tokyo, I'm not so sure yet, but I have the impression is as warm as Bilbao, only with less rain. I spent a summer there and it was friking hot. It's got four very marked seasons. Huge metropolitan area (35m people), but not many foreigners, about 2% and they're mostly from East Asia and some Westerners that work there.
My city, Bilbao:
The Guggenheim Bilbao Museum and Iberdrola Tower (biggest renewable energy company WW, they own Scottish Power and some American companies).
No troll is too much for me to handle. I rehabilitate trolls, I train people. I am the Troll Whisperer.
