Fallout would be perfect if set in England, not because its my home country - but because it would have the perfect atmosphere. There would be more variety, all American buildings and the way its structured is all the same. Wembley could be a major settlement for the Enclave or BoS. And their are so many more landmarks than just tall pointy buildings and a giant hall. Also our houses arnt made out of wood - so there would be more intact. haha.
I don't know which part of England you live in, but I've never seen a 50's coal town that looked anything like America. Our buildings are smaller, closer together and in some cases older.
Basis of fallout: retro futuristic post apocalyptic world based on what americans thought would be the future. I'll agree change can be good, but do you want bethesda to make an attempt and fail at setting a game in a different country based on what their views of the future would've been?
Resistance: Fall of Man on PS3 is very much a retro futuristic Britain, and despite being an American dev team, it worked really well. I've been to most of the places in the game, and its fairly close to the British Austerity 50s (as opposed to the USA's pop-culture explosion). A Britain actually set in the Fallout future would propbably jsut be alot more degraded. British Sci fi of the 50s is almost nonexistent, but since our 60s were pretty much America's 50s, much of it could be taken from Sci fi of the 60s. Which would mean more dystopian governments, RP accents, Sten guns (they're everywhere in UK sci fi. Must be cheap props) while still having, for some reason, rows and rows of postwar 50's housing. The rest of the technology would pretty much be like the american stuff, but all beige and avocado coloured.
That said, while I'd love this game to happen, I don't think it would be a good idea to take Fallout away from the American 50s aesthetic.