Fallout: London would be so sick.
I would love a Europe based Fallout, explore the way american-style capitalism played on European post-WW2 values.
Everyone insists the whole point of Fallout is about the American culture aspect, but I don't see what more we can get out of that.
And while America/China were the big Fallout powers, we've still not seen exactly how the war started, and I don't think we'll ever get any more info on that in future games.
So I would enjoy either getting to see the Chinese view (which might be interesting as we see the remnants of this ultra-communist nation, compared to ultra-capitalist), or a third-party European view.