I think a good setting for fallout 4 would be in China. Your character could be from a bunker in China, maybe near Beijing, set up by the pre-war U.S government to make sure that China does not recover from the war, effectively winning the war. In the year 2300 it is considered safe to leave the bunker, and a scouting party is sent from the bunker to gather intelligence, It never returns and your character is sent out to find out what happened to them. He then finds that the Chinese government is trying to seize control of Beijing, and the Enclave is also sending troops over to China.

I kind of want to see it stay in the U.S, not for any real reason but to see the interpretation of a post-war city that I know a litte bit about. Beijing is good, but through the lore and everything, I would expect it to be nothing but an absolute crator, the U.S would annahilate cities like that in a country that attacks us with Warheads. capitals and the largest cities would look like the Whitehouse in FO 3. But it would be interesting to see it on the opposite side. But to see it from a 3rd party would be even better, Britain after the UN broke up, and the cities would probably stay more intact than any in China or the U.S due to the early drop out.

Personally I'd like to see something larger than just a city, an entire state open to travel, (mainly so that vehicles could be added, nothing big, just maybe those motorcycles that litter the street being repaired) I'd say Pre-NCR California, Detroit Michigan, Miami Florida (i'm saying state too so to cover both the major city, and the entire state for a larger map) maybe even include canada somewhere since it was annexed.

My favorite choice would probably be detroit since it could have a huge multitude of areas, cities set up on overlapping overpasses, sewer systems turned into cities, and then of course sections of the main city being different cities.

I'd also like to see a mixture of the factions in there, some enclave cities (mostly just 1-2 large cities, no longer influenced by a corrupt system, taking a more people friendly role, not so much a [censored] of a faction) Definetly bring back BoS, maybe a small influence of the NCR (budding into the new wasteland) a new faction to represent the new wasteland (for example the New Democratic Republic of Detroit or NDRD, crappy name but just an example. Maybe having a serious conflict with the NCR while remaining independent from Enclave and BoS rule.)

I'd also like to see the BoS trying to have a more colonization role, still a technology hungry group, but taking over cities and towns for a workforce, while offering protection and power etc. A vault dedicated to vehicle work and improvement to allow infrustructure in the post-war society experimented by vault tec. More social experiments such as a vault designed to create new technology based on war, or a friendly aspect (or even two vaults, one based on war, and another on medicine and longetivity of people)

I'd also like to see another Super mutant society, full of inteligent beings (both the low intelligent, and the high inteligent, friendly, and even co-existent to the humans) Another Ghoul society, maybe even two, one dedicated to a safe haven, and integration into human life peacefully, and another dedicated to revenge against the humans, looking to make ghouls the supreme race. With a crazed sub-group that want to use radiation experiments to turn people into ghouls.

The Followers of the Apocolypse should also return, maybe even having much more of a presence in the wasteland, maybe even semi combined with another group, or working with a group of similar purpose.

Please use one of these topics.

http://www.gamesas.com/topic/1378191-fallout-4-speculation-suggestions-and-ideas/

http://www.gamesas.com/topic/1369182-official-future-fallout-locations-suggestions-topic-15/