I voted for Russia. Why, because as I understand it, they could do it almost immediately. I think they have a Russian pavlion at DP, so it would be a simple matter to clone.
I know many of you hate clones, but my chances of seeing other parks are slim, so I'm ready for all the clones we can fit in, as long as they don't replace our good stuff.
And yes, I understand the Russian pavilion features a 360 movie, of which there are already 2 and 5/9 at WS, but any new country would be better than none, especially if it had an honest to goodness attraction, even another 360 movie.
At times, I've heard proposals for pavilions for Spain, Israel, Switzerland, and of course the Equitorial Africa that came on the original park map. I'd love to see them all.
While we're in World Showcase, let's do the originally planned German Rivers attraction, the COP-type theater show proposed for Japan and come up with something for Italy, Morroco and the U.K.