I don't know jin Yong (what would I read from him first as european? Any recommendations?)
But I tend to dislike the overarching glorification of Tolkien. Surely an impressive writer and world-builder but surely not the only one and not necessarily the best.
It can be difficult to get into reading JY as a Western reader as he writes in extremely poetic language. There are a lot of great articles on the difficulties of translating Chinese poetry if you're interested in the subject.
Instead -- I suggest you watch some of his live action adaptions! The Smiling, Proud Wanderer is my personal favorite JY story, and my favorite drama rendition is the 2001 one starring Li Yapeng. He is probably best known for the Condor Trilogy (The Legend of the Condor Heroes, The Return of the Condor Heroes, and The Heavenly Sword and Dragon Saber) and although I loved the first I was never personally that into the latter two of the series. Probably his greatest work is in my opinion Demi-gods and Semi-Devils, although that might not be a good entry point into the series. I would look at TSPW or TLCH first :)
And well, Tolkein will always hold a special place in my heart. But I do agree that he is slightly over romanticized as an author.
I've watched Laughing in the Wind (2001, 4 seasons with 10 episodes each) but with English subtitles as I don't speak Chinese and have to warn the other poster that it's availability is extremely limited last time I looked.
I think that it's quite reasonable to consider Tolkien as one of the best world-builders in the Western canon. But that is unsurprising, given that the man basically devoted his entire life to constructing a single imaginary world - he was a world-builder first, and writer second (and far better at the first than he was at the second, IMO). Most authors create a world to tell their stories in, and it's only as detailed as the story needs it to be. Tolkien wrote stories as, basically, illustrations to his world-building. Most of them didn't even get cleaned up to be publishable until long after his death.
I think it's pretty hard to answer this question because what Tolkein is good at and what he is bad at are two sides of the same coin.
Tolkein presents an extremely fantastical view of the world and ascribes to what I call "cosmic morality." There is obvious, pure good and pure evil, and in a way the Universe intervenes to make sure that pure good will win out in the end. I don't mean this in a Deus Ex Machina way, by the way, as cosmic morality is justified within Tolkein's universe. I think Breaking Bad is a good example of this as well -- the Universe has passed its judgment on the characters it deems necessary to pass judgment on, and it works within its story without detracting from it or seeming like a Deus Ex Machina. So much of the criticism of Tolkein in the modern day, to me, surrounds this concept where he ascribes to the idea that the Universe will eventually judge sinners and saints. That being said, it does not and should not detract from the sheer magnitude of his creative work, as well as his linguistic ability.
George RR Martin, is, I think, an obvious counterpoint and much of his writing is driven by a distaste for this amount of cosmic morality. If we were to harken back to amazing TV, GRRM is more like The Wire -- they choose to present the world in a way they deem "factual". But in doing so they lose some of the higher fantasy elements that Tolkein's world building is known for.
So I think when you ask the question of who is a better world-builder I think you need to start with asking whether or not you want a cynically real depiction (ala GRRM) or you want a story that justifies it's heroic deeds (ala Tolkein) first. Because, in my opinion, they are hard to compare.
"There is obvious, pure good and pure evil, and in a way the Universe intervenes to make sure that pure good will win out in the end."
There is no such thing in either the Silmarillion or the Lord of the Rings: in the Silmarillion, Melkor is taken beyond into a different dimension, yet there is so much damage that this is hardly more than partial damage control; and stopping The Enemy causes an even greater tragedy, that of everything wrought with the Three Rings to fail and fade, resulting in elves having to once again leave Middleearth, that place where they awoke and hold so dear. Hardly can this be called "good versus evil" or either side winning, and if so, it's a phyrric victory for both. Nobody wins in the end; the inevitable is just prolonged yet again through the rise of men at the expense of everyone else. The way Melkor set the stage, Ainur played it, and Sauron finished it, there could never be any victor, good or evil. It was a perfectly balanced system. It was never about Black-White and especially it isn't about good winning in the end, since the victory causes even more tragedy.
I had hoped that the Breaking Bad reference made more clear what I meant by cosmic good/evil. It has nothing to do with the idea that the One Ring is good or evil, but rather that the Universe has morality ascribed to each character. We leave LOTR feeling for the most part satisfied by the story. I suspect A Song of Ice and Fire will not have the same satisfaction.
But this is, once again, my own subjective opinion and theory. I don't even think there's anything inherently wrong with cosmic good! In general, I wish media would be more willing to take a stand when they choose to display violent acts on television.
"We leave LOTR feeling for the most part satisfied by the story."
I leave LotR feeling terrible pain, loss, and sadness: the main protagonists are forced into exile to another world (planet), Valinor; they can never come back; the fate of the mortal ones (Bilbo, Frodo) will forever remain unknown, they have to forever part with their friends and family, and Middleearth remains behind bereft of elves, their beauty, grace, and intellect. How this is a satisfactory story I am incapable of fathoming, not because any one side won, but because the ending raises even more questions than it answers.
Wouldn't the Eru's resurrection of Gandalf count as a pretty clear example of the Universe intervening to make sure that pure good will win out in the end?
Neither Gandalf nor the Balrog could really be killed, in spite of Gandalf implying it, because they are both Maiar, the powers of the world, and their existence is bound to that of Arda. To kill them, Arda would have to be destroyed. Same goes for Sauron, even after destroying the One Ring. They're all indestructible in the same way that a planet is destructible.
Gandalf being sent back ("I was sent back") is an act of keeping the events in balance, not Eru intervening so that good would win, because in the end, even with him doing as much as he did, everybody loses. Gandalf knew this full well, and that is why he did not want to go to Middleearth. He was afraid. He did not want to go stop Sauron. Manwe ordered him and the other four Istari to go anyway and the other Valar backed him up in his decision.
Even if you take the position that Eru intervened, there is always that moment when Eru Illuvatar tells Melkor "know that nothing you do will ever be without my will and intent of you doing it".
Not competing on world-building per se (inventing few languages requires proper linguistic background), but on other aspects, Malazan book of the fallen series is an amazing read. World is just more interesting to dive into. Till I had read it, Tolkien was #1 fantasy for me. Afterwards, it seemed bland and a bit boring. But that's me, some people drown in complex parallel stories and heaps of characters.
From what I heard Wheel of time is similarly awesome, but no first hand experience with it yet.
The Wheel of Time has some great world building, but also some terrible. The Wheel has a lot of different cultures that all feel like they have an identity.
However Wheel is mostly great for its broad (epic) scope of the central conflict and how this is told threw characters.
George Orwell certainly was a successful writer (in the sense that he became famous and sold many books), but not a world-builder. 1984 is a rip-off from Zamyatin's novel, "We".
Ironically, Orwell wrote before WWII that Aldous Huxley's Brave New World (1932) was heavily inspired by We (1921). Then he wrote 1984 (1949) which borrows even more: it's the same story, with more romance and a more mainstream narrating style.
Things like 1984 don't really count as fantasy though (unfortunately) as they were an extrapolation of things that were already happening in the 1930s and 1940s.
But I tend to dislike the overarching glorification of Tolkien. Surely an impressive writer and world-builder but surely not the only one and not necessarily the best.