Extended Cut, yep.
The international cut may be better.
As it happened a couple of times with his own films, Kubrick found out what he was actually interested in very late in the process. There were some scenes shot that explained the mysterious appearances in the hotel room in the final act (including the guy in the bear costume), as Jack Torrance was browsing through the archives of the Hotel.
He ultimately chose to focus on the Jack-Danny relationship, and Jack's own vulnerabilities, while the novel and the script were more about the hotel being an evil place.
The original cut, that played for one weekend in LA and New York (five theaters each), had an epilogue, where the hotel manager visited Wendy at the hospital, to explain that they hadn't found Jack's body (just after the shot of Nicholson frozen to death). He notices Danny playing outside the room, and he throws him a ball that bounces exactly the same way the ball thrown by the "twins". They spent an entire day getting the bouncing right. Cut to the final shots in the empty rooms of the hotel, with "Midnight, the Stars and You" playing, and the picture of the 4th of July ball.
Shelley Duvall loved the scene because it was very Hitchcockian (the manager knew and was manipulating them from the very beginning). But losing these two minutes contributes a lot to the shock of seeing Jack in the picture, that would have been much more diluted after this kind of interlude.
It's a pity that, due to the UHD Blu-ray, the international version is now getting slowly phased out. That's one of the questionable choices made by the estate and Leon Vitali. I'm sure that there are economic considerations, but it's still a mistake to me.
The official reason for the shorter version was that American box office started soft for The Shining and Kubrick didn't want the film to lose money, as Barry Lyndon did, but I think that there are other motivations. The international cut is tighter, and excises mostly material from the original novel, at a time King was starting to be vocal about his criticism of the film. Keeping the longer cut in the US would keep King "happy", while Kubrick would roll out his preferred version in other places. Ultimately, Kubrick and King found this arrangement, under which King wouldn't make more comments about Kubrick's film, in exchange for gaining back the adaptation rights after 15 years or so, hence his miniseries.
Also, do you remember the stuff when Danny drives his tricycle, with the noise that starts as soon as the tricycle goes from carpet to hard floor? It was unplanned. When they shot the scene, they noticed the discrepancy in volume and they were trying to fix it. At some point, a random crew guy said something like, "But you know, it's actually a cool effect." Kubrick thought about it for a few seconds, and he agreed.
