To be quite frank, I'm actually a little surprised at the small amount of people who say they'd like to live in Japan. I mean, really... Considering this forum... But anyway...
Northern Germany - The whole heritage thing comes to mind, but I can also visit the seaside and still have access to the other places in Europe I'd love to visit but would rather not live in.
California - The weather's nice, and I get the chance to go see a Ducks game every once in a while. Housing would be expensive, though. :P
England - You know what? I actually like what people consider to be crummy weather, not that it's crummy all the time, but the whole atmosphere is something I'd like. Heritage also pops up, but isn't really very significant.
Japan - It's something I've wanted to do since I was a little kid, seeing how I wanted to help make games for Nintendo at that age (and if I can, I'll do it. Mario, here I come :) ). The culture, language, and history of itself as a nation is also a very interesting topic.