I think independent or House ending.
They do a good job of vilifying whomever you're not actively siding with. However, they also repeatedly question authority and centralized government.
On my first play through I was heavily siding with the NCR, though I intended on siding with Yes Man in the end.
Once I met Cooke in vault 19, I pretty much stopped helping the NCR at all and focused on helping more of the smaller groups.
In Cooke, you had the 'leader' (or maybe 'creator' is more accurate.) of a faction whom is initially portrayed as an antagonist, but then explain he was only a villain because he hated the NCR. Which a lot of people in the wastes do. He was just more active about it.
This is someone who has a lot of sway over the more sociopathic types in the powder gangers, whom are really only doing whatever is needed to survive after having been labeled criminals by some half assed attempt at government rule.
Even the first powder gangers you encounter were going after a member of one of the biggest corporations in the wastes, and that's fine by me.
Goodsprings never at any point really feels threatened by the powder gangers. They know they'll need to deal with them at some point, and they do so.
Ideally I think there would have been a peaceful solution, and maybe there is. My second character was considerably less of a talker than the first. But that sets the theme of: Yes there's chaos, and violence in anarchy, but it's better than the violence and oppression of a group like the NCR.
My point is that in the first couple towns. Goodsprings and Primm they heavily emphasize the theme if independence, while expressing a general dislike of centralized government (In Goodsprings) And the willingness to join one in dire situations(Primm). But also detail how loose of a hold the NCR has on the area.
Establishing independence for these settlements in some ways helps the NCR(For the time being.) because they don't need to expend as much in the way of resources, etc, etc. Over all, it's better for everyone.
As I already stated, they go on to alter your perceptions of things throughout the game. But as good storytelling goes, I think those first few experiences really set the theme for the 'ideal' scenario in the game.
They also turned the Great Khans from one of the major antagonists in the west, into a humble group of peoples, simply trying to live freely. Again leaning towards the social-anarchy theme. Straying from a more black and white perspective of the original games.
I think it could be a House ending based on the fact that if you side with Yes Man, there doesn't seem to be any sort of control over the securitrons, they just 'Keep the peace' at all costs, which turns the strip into such a dangerous place that the Followers leave.
Also, the fact that you lose karma for disconnecting House despite that he was a batshit crazy, paranoid, power hungry lunatic.
I lean more towards the Yes Man ending, because of that previously set theme of no centralized powers. But then since House only cares about Vegas, maybe he really is the best way to grant it independence. The outlying settlements will still be free.
I think in the long run, house will disappear. He kept himself alive for that long waiting to get the chip back. That was his goal. Opening the doors to the 38 was setting the stage for the end of the game.
All the cards are on the table and eventually he's going to be knocked out of power. May as well be done by the Courrier.
You can't count on one person, or any one set of ideals to take care of a society for any extended period.
In my ideal scenario, you would establish some sort of agreement between all the smaller factions. Followers, BOS, Khans, Powder gangers, Boomers, etc to ensure the dam and Helios 1 provide power to the area(Or destroy them both). You'd knock the NCR, Legion and House out of the picture and destroy the securitrons.
Set the stage for long term independence, then remove it's greatest enemies.
What of the rest of the legion? The legion needs to be expunged from Fallout history the way Highlander 2 is ignored by everybody but Robot Chicken for satirical purposes.
The fact that they are portrayed as having grown as large as they have is an offence to the Fallout universe and the title of 'Super Villain.'
Their ridiculous pot and pan, miniskirt armour is just... Ugh.
There's no excuse.
They are a small time gang with a short sighted plan. They'll fall further than the Vipers and Jackals.
Without Cesar and Lanius with his stupid fucking ugly mask, the people will go back to their tribal ways and never speak of the time they were ruled by stupid, ugly, imperialist wannabes who couldn't even craft their own armour and weapons from the millions of abandoned cars in the wasteland, but instead opted to use cookware and lawnmower blades. Yet somehow they were practically bulletproof!
No matter what happens, yeah, I doubt it will have any impact on the next game. It will just be established history.