I really like Russia, but I'll concede the Western front, if I must. As for specific nations, I'm all for whatever you guys decide. It seems to me that, if we're playing the allies, it makes more sense from a roleplaying point of view to be British, just because I speak their language and understand more of their culture than I do France. But again, I'm game for whatever.
EDIT: I'm for whatever, so long as it's structured.