I'm sure there have been many, many threads and posts on this topic. I am attempting to approach it from a different angle than usual - though even that I'm sure is false, there have probably been discussions at least of the nature of what I'll attempt to get at here, but I searched and couldn't find anything, so here this is.
First, I'll link this article which I found interesting;
http://www.theguardian.com/culture/australia-culture-blog/2014/feb/21/writing-video-games-can-narrative-be-as-important-as-gameplay
The article is obviously a bit dated, but it brings up some important and still-relevant points about narrative and gameplay that I feel are really worth considering. Many gamers (and seemingly developers) are quick to dismiss storytelling as taking a back-seat to gameplay, and they have a point. Games are about engagement, about doing and participating rather than passively taking in a story. This is what distinguishes games from other forms of storytelling, and is their most desirable asset. That doesn't mean however that storytelling/writing is not important, or even that it's not as important as gameplay. What it means is that storytelling needs to be thought of differently in the context of video games.
Its this point that I'd like to expand upon in the context of TES and Fallout (I know this is a TES thread, but there is no BGS thread, and it all applies).
Now it's safe to say that pretty much everyone can agree that Bethesda has issues with its writing specifically in regards to storytelling and dialogue. I find they actually do quite an excellent job of the lore, or the world-building aspects of writing. As far as I'm concerned the worlds of Morrowind, Oblivion, Fallout 3 and Skyrim are the primary reason that I love these games as much as I do. However, I believe BGS has problems with their actual approach to narrative and this is exemplified by Fallout 4. I don't intend to dissect problems with past or present games so I won't go in depth there but the whole thing does leave me concerned about TESVI, thus this post.
The problem as far as I see it is that Bethesda tend to think of the 'story' as the quest-lines or whatever, the big events. So yeah, you need that stuff, at least some of it (I really wish they could be more creative and come up with something better than destroying the super-powerful badguy who wants to kill everything for the main quest, and the destruction of the guild for the guild quests). For the player though, that's not the story. The players story starts before that, and ends... well, when they stop playing, but potentially and in most cases, after.
I'm attempting to get at the conception of what the story is in these games. In practice, the story is the players experience of this world. The best part of these games is exploring and interacting with the world - the most authentic 'storytelling' being done in these games is the natural storytelling that arises from the players interaction with it. It is this aspect of these games that seems to be getting less and less focus however as they move forward. I somewhat understand that in terms of a design decision - doing this type of storytelling requires a lot of subtle refinement in just about every area of the game; it is also often not noticed, not appreciated, very complex - and as such, can be confusing and intimidating for new players. I contend that it is worth it. If it were truly a focus, and handled well, it would be noticed and appreciated, and it is this type of quality that has a lasting, generational effect in the fan-base. What I'm talking about is attempting to make the world and specifically, it's characters and creatures, feel as though they exist without the presence of the player; and further that the presence of the player and his/her decisions affect them.
Now this does have to do with choice and consequence, but the point is that the emphasis is on consequence. The big world-changing choices almost never work in practice, as there are just too many angles that one could conceivably be coming at these choices from, and the word has to change too drastically afterward for it to make sense if the game is to continue. Consequence however, is the single best storytelling device these games have. This isn't strictly related to the complex interactions of player and npc - a 'true' economy is one great example. Having certain goods be more plentiful in certain areas and therefore cheaper, while more scarce and therefore expensive in others is one small way to achieve this - the ideal of course would be a complex and robust system that included purchasing businesses, and the ability to sabotage businesses/goods producers to drive them out of business, etc. - this feature alone could open up an entire avenue to experience the game from.
I personally love the old-school RPG mechanic of the 'critical fail' as a storytelling device that flows from gameplay; too low a skill in something and risk the chance to critically fail - to not only not succeed, but to harm yourself in the attempt. The (small) chance to trip, if you move too erratically too rapidly (perhaps combined with low agility). Mechanics like these force on-the-spot problem solving, and generate stories on their own. I do understand why it's not for everyone but I would throw in realistic needs, diseases, injuries, and reaction to weather/environment as well - these are clearly becoming popular features, I'd like to see them incorporated at least as an optional with the base games moving forward.
NPC's reacting to the weather by equipping appropriate items, seeking shelter from rain/snow, reacting to danger more appropriately. NPC's reacting to the player more appropriately is of course huge. If you steal from someone and get caught, sure you pay your fine or whatever and can avoid jail, but that person should remember - they no longer trust you, depending on what you stole/attempted to steal, perhaps they hate you, and depending on their constitution, perhaps they'll attempt to kill you, or have you killed. If you're a famous warrior, you should be revered and an infamous murderer should be feared and reviled - conversely, a nobody should be overlooked, uncared for, and often treated like rubbish. You won't be offered quests by every single person you come across who "also" happened to be looking for someone just like you - regardless of who you might be. Doing certain quests, or certain actions will prevent you from doing other quests. Certain quests or quest-lines can't be accessed until achieving certain status in the world, or having completed particular quests. Again I understand why it's not for everyone, but another optional feature I'd love to see - every NPC can die. Those that should be hard to kill, are - either because they have guards, are located in well-defended locations, are very powerful themselves, or all of the above. A variety of AI packages would be helpful - Beth base AI being a great low-level or 'stupid' AI with higher level characters receiving more AI 'abilities' /more refined AI; such as high-level mages or stealth characters having advanced stealth detection abilities, higher level characters in general having better survival AI. Group-fighting tactics; there are spells for healing in this world, why are battlefield healers not a standard thing? Ranged attackers should attack from range, seek and attempt to attack from cover (a real cover system would be nice) stealthy attackers should attempt to sneak, and frequently use poisons - (which are actually dangerous) heavy warriors will rush in headfirst, while light/medium warriors will use movement and timing. Detection AI needs a ton of nuance.
The simple act of being able to climb ledges would open up yet another new world of gameplay, especially if it were fully-fleshed out (meaning breaking into buildings through upper-windows, jumping and grabbing ledges, running along rooftops, etc.) The gameplay/storytelling opportunities it would present are enormous.
I think I've pretty much made my point; the most engaging and authentic storytelling that happens in these games, and the type of storytelling that they are uniquely equipped (but under-utilized) to deal with is the organic storytelling that comes from the players interaction with the depth and nuance of the world. I do admit that some of these features can turn off some of the broader base of fans, but I believe that if handled properly would be appreciated by both casual and 'hardcoe' fans alike.