No one mentioned Western Washington State... there's Puget Sound, a strait of water surrounded by lowlands, highlands and mountains, a big lake with an island on it and overall it's probably the greatest mix of land and water I've seen in an area no more than a hundred miles wide ;P
Yes. And we're also quite diverse. Though we are lacking a general shape for the region to me.
Heres my top 3:
1) New Zealand with part of austraila. So we get part of the mainland with Sydney and a island.
2) We could get the UK and it could be connected to Kalos by the channel tunnel.
3) Florida, though swamplands were annoying in sinnoh and kalos (why were they there? :P
It'll have to be a place where the developers can go and do some first-hand research. As much as they just throw whatever Pokemon into a region they feel like, they've made an effort to have the places be reminiscent of the real areas they're based on. So Australia wouldn't be picked just because Australia has all those unusual animals. They'd want to pick it because it's got all kinds of landscapes and culture that could find its way into the games.
And that's why I don't think they'll go to places like Africa or the Middle East. Lots of places there aren't too safe or friendly so they won't send people there. Australia seems like it would be a pretty good pick, but so does the UK. The UK though is bound to be a lot like France, or at least more so than New York is, so that doesn't seem like as much of a change as a place like Australia would be.
Wouldn't mind if they picked somewhere in Asia like Taiwan or South Korea, or if they went to South America or the Caribbean.
Why not go back to America and go to the west coast, like California?
Or Canada. Just imagine the a maple syrup pokemon.... it'd be the new Vanillite.