As for the extended versions of the other two films, while I cherish most of the added scenes and shots, I tend to feel the exact opposite about many of the additions. Return of the King.
Perhaps the best example of this is Gandalf’s confrontation with the Witch-King of Angmar during the siege of Minas Tirith.
In the extended version of Return of the KingJust before the epic Ride of the Rohirrim, Gandalf and Pippin approach the mad Denethor, and the Witch-Lord descends before them. The Nazgul draws his flaming sword, and its power shatters Gandalf’s staff.
Not only does this not happen in the original, but in the book, after Gandalf finds out that Éowyn is dying after her battle with the Witch-Lord, he regrets that he should not have faced the Nazgul, thinking that maybe he was destined to do so.
Before you quote the “no one can kill him” rule, let me say that it’s true. But in Tolkien’s mythology, wizards are not humans who learn magic, like Harry Potter. Wizards are angelic beings, not “human” in the sense that they are not human. In that sense, Gandalf is just as “non-human” as Éowyn, so he could probably defeat the Witch-King.
It’s one thing for Gandalf and the Dark Lord to have an epic showdown in an expansion; Return of the King Gandalf may ultimately lose (though he may survive), but having his staff destroyed just because another man drew his sword? Nah, give them a real fight or skip it entirely.