Fallout NV is a far better game in pretty much every respect but one: it has better characters, more believable environments, better gameplay, a better plot (one could even say it simply has a plot), more choices with deeper consequences, etc. The one thing it lacks is not so much a fault of the developers as it is a "fault" of natural evolution and also a case of false expectations from the players' side: as some people in previous posts have already mentioned, NV is a game about a future civilization rising from the ashes of a nuclear holocaust, and not about the nuclear holocaust itself. As in, the holocaust is more of a historic event by that point and not an aspect of the contemporary world.
It's been 200 years after the War and yet in FO3 you still find unlooted supermarkets and pharmacies, skeletons of people who died during the nuclear explosions, "forgotten" locations that "no one else ever explored", destroyed buildings still standing, people still living in filthy shacks and treating clean, non-irradiated water as a rare commodity (!), etc. You also get a Wild West frontier-type setting where people are living in isolated communities and trade is limited to a few daring merchants traveling between them in a no-man's land rife with outlaws, and where organizations like the BoS or the Enclave can do pretty much whatever the hell they want because the world is in a state of constant dog-eat-dog and might-makes-right.
Now compare this world with the world of NV: you get people leaving in... oh what the hell, I'll call them cities, even if what we 're shown in the game is seriously lacking in size (and also lore-wise we learn from the NCR citizens that back in California there are actual cities, something that older players have known since FO1), you get a huge number of people living under a single governing body, you get an actual government with an actual standing army (but one which still retains that Wild West, kids-pretending-to-be-adults feeling), you get a BoS that has gone into hiding because it refuses to accept that the world has changed back to where a bunch of gung-ho supersoldiers have no business running around treating the world as their personal playground and its inhabitants as their inferiors, you get the once almighty Khans having been reduced to a sorry drug-cooking gang of outlaws, etc... but most importantly, you also get electricity, clean water and fresh food!
In other words, FO3 is all about surviving in a devastated world where the devastation event is still fresh, and where the until recently pampered survivors are struggling to cope with a suddenly hostile environment. It's a world where survivalist nutheads, military-type tough guys and of course "lone riders" (like us!) get their chance to shine, either by protecting the weak or by becoming their "kings" or even their worst nightmares. It's like a movie set in the aftermath of a huge hurricane, where people exit their basements and experience the shock and the despair that comes from their world having been destroyed - only in FO3, the WHOLE world has been destroyed. This allows the player to actually feel like exploring a new world, in the "archeological" sense that someone above me correctly mentioned. The setting is post-apocalyptic in every single way, and it's really much more true Wild West than NV is with its casinos and its cowboy hats and its cowboy accents.
NV is the complete opposite. It's a world where "something" happened 2 centuries ago, but which is (or should have been*) pretty much ancient history by now. You get the Wild West in its final days, where the reach of the law is more or less indisputable and the few bands of stubborn outlaws that remain are of minor importance. The feeling here is not one of despair (oh God everything we knew is gone what are we gonna do) combined with excitement (a new world where everything is possible, yay!) but one of hope (things are finally looking up again) combined with sadness and a longing for a simpler past where a man (or a woman I guess :P) could make his fortune simply by being tough and working hard. As I said, it's exactly like the final days of the "last frontier" that was the Wild West before "progress" came stomping through with its trains and cars and what have you. NV is set in a pretty much already explored world, where the point is not to cope with the lack of civilization's luxuries but to deal with its increasingly restrictive attitude toward its "citizens".
So, the issue here is that FO3 and NV are made for completely different audiences: the first is made for people who like exploring the despair, but also the hope and sense of freedom and wonder that an "abandoned" world brings on the table - it's essentially a "remake" of FO1, at least in mood. The other is made for people who enjoyed the world of the first 2 Fallout games and were longing for a game set in that world as it was left at the end of FO2, which is a world where the problem at hand is no longer one of everyday survival, but rather one of learning to live together again as a whole instead of individuals, to build a society like we used to have, in essence to rebuild our lost world. In other words, Fallout's world is no longer a post-apocalyptic one.
The problem with FO3 is that, for marketing purposes, it used the timeline of FO2 and set itself 200 years after the War, when what it really wanted was to be a post-apocalyptic game, complete with survivalism and mutated critters and dangerous outlaws and gunfights and unexplored "mysteries of the old world" and still-waiting-to-be-found treasure and what have you. But all that doesn't make sense in a world set 200 years after the nuclear holocaust, and even if one could make the argument that the world COULD have been like this 200 years after a nuclear holocaust, it still doesn't make sense in the Fallout setting where the world for good or for worse has supposedly been rebuilding for at least the past 100 years (since FO1). In other words, Bethesda's world just doesn't make sense. But really now, what can you expect from the guys that in FO4 made it so you can find "ancient" sealed vaults which in their depths hide "ancient long-lost tech" such as modern chems, booze, and even "pipe" weapons? Talk about world integrity :P
So that's the real issue: not only is FO3 worse as a game when it comes to individual elements (characters, plot, locations, gameplay, etc), something which could even be hand-waived as a subjective opinion, but it's also completely absurd in terms of world building. Because, even if a pure post-apocalyptic setting might be preferable to some people (myself included), a coherent world is even more preferable, especially if we 're talking about a sequel set in an already established world. That's the real reason NV is objectively a far better game: because it respects its predecessors and because it creates (or rather builds upon) a living, breathing and ultimately believable world, even if subjectively it may not be the world some would prefer it to be.
Now, if only we could have a believable world set in a pure post-apocalyptic world and not 200 years after the [insert world destruction event here]!
*The bane of post-apocalyptic absurdity for the sake of "drama" is evident in NV as well, things like people living in filthy buildings with punctured walls and skeletons lying around etc. But I believe Bethesda as a publisher might have had a hand here, enforcing on Obsidian their "trademarked" style of the Fallout reboot. Oh well.
Post edited June 18, 2017 by Nocifer