Having played the games Baldur's Gate 2, Planespace: Torment, Morrowind and Oblivion, aswell as The Witcher. I have to admit I am unsure.The great world of Baldur's Gate with its legends and races would be a great place to toy around. The Multiversum that could be accessed from Sigil and the pure awesomeness of the posibilities of places to go and people to find would be beyond anything a mere human could handle, as it is a amazing place. Tamriel, with its various countries and races, its legends and magic. What would I give for such a life? One could d anything. However, I deeply believe that the only world that would portray the hardship of the people's lives correctly is The Witchers.As the racism toward elves and dwarves is exaclty that, racism. Contrary to the elves hating drow, because they're evil, or the believing of animal races inferiority.The only world which I believe actually would portray how it is living there is The Witchers.As that I believe that the others do not fully portray how it would be.Mostly likely I'd be some sort of wandering Scholar in Geralt's World.
The Witcher's world is gritty that is sure. But I believe that Forgotten Realms universe is just as dirty and gritty but the difference is the form that the game takes. In baldurs gate you have another style of game and it dosn't suit very well for the adult perspective. It is isometric perspective with characters that are animated and not intended to look real. The Witcher technology with motion capturing is more recent and allos for a more detailed experience.If you remade BG now, using the same tech usied in the Witcher, made it into a OTS or 1st person perspective, you could just as easily add homless kids wandering the streets of Baldurs Gate, shoe peasant farmers and hookers alike, have people plow fields and doing backbreaking labor. You could show an evil sorcerer in all its powerful glory rip the guts out of that seeet maiden in sacrifice.I mean t is not that such things do not happen on the Sword Coast, it is jut that the tech of the game at that time didn't allow for such details. Also, ther audience should be taken into account. I think BG was intended for a wide age group whereas The Witcher is a much more adult audience. There is also the case of magic. In TW magic is restraint, limited and difficult. To master it is hard and you can get killed. But in fact in other games it is equally dangerous but they just don't show it when you cast epic level spells as if there is no tomorrow. Thy just skipped the fact that you studied a long time and to narrow it down to the actual game, your game starts you off as a mere apprentice that can cast Light and an acid splash. That is the trsucture of the game that you progress and cast epics at the end, otherwisde you got a game where there would be no suh progress. In TW you have little progress, just a few signs and some power levels and abilities that you click onto it. But that doesn't mean that in FR you would not study long and hard and risk life and limb to master magic. The danger of it is mostly in the Lore of the realms, stories of spells gone out of hand, demons summoned and not dismissed. So it is the way the game looks that might make you think TW is more 'real'. But I think it is the difference in approach. There is suffering in Tamriel, FR, all these fantasy universes. TW just chose to show them as part of the experience of the story whereas other games let that side to embrace another type of gameplay.But I'd love to see a new TW style game in the Sword Coast and walk through cities that have a dirty and gritty look and feel to them. Rememebr that in BG you also could enter the sewers down the city. They just looked clean and plain; that was the technology and computer limitations of that time.
Tough choice, I love The Elder Scrolls and The Witcher, not a big fan of the Forgotten Realms. If I had to choose between Tamriel and Gearalt's world, I guess I'd choose Geralt's world, since not everyone in his world can wield magic which means I'd be less likely to get burnt to ash by some homicidal maniac bent on my destruction. I'd have a better chance of defending myself and surviving against a sword wielding enemy lol
I don't know for sure if I would want to live in Geralt's world.I'm kind of a big fan of Indoor pluming 
If I wake up to find three portals in my room, I'll scream and sue game developers(or that kind of dangerous people) .First, because I would be frightened dead if I had to live in this kind of reality. And I would not live long . I am very clumsy even with a kitchen knife . I don't like life-size monsters looking at me, licking and drooling and gnawing ,with roars and shrieks. I like monsters safely kept behind the screen. Then, I have never seen a videogamer in these worlds ; well, it is my favourite hobby .Besides killing, running,plotting against vicious magicians or ferocious warlords, what would have I for entertainment ? Playing poker dice in Temeria ? Then, I must be allowed to cheat, saving before each game. I don't want to lose my painfully earned orins .