I "grew up with" a specific translation of Lord of the Rings into Norwegian, for example. There are two. They are very different. But the editions also differ in whether they include the appendices, whose illustrations are used, and more.
Are we talking material plot or characterisation changes?
>English: I will not tell anyone the secret.
>Bokmål: Jeg skal ikke fortelle hemmeligheten til noen.
>Nynorsk: Eg skal ikkje fortelja løyndomen til nokon.
Source: https://www.visitnorway.com/typically-norwegian/norwegian-la...
The title differences are also a good illustration of how different it can be:
Bokmål: Kampen om Ringen, Ringenes Herre (the first one is literally "the battle for the ring")
Nynorsk: Ringdrotten
An example is the name Bilbo Baggins. In the "canonical" Norwegian translation, he's become Bilbo Lommelun. "Lomme" means pocket, and "lun" means snug, warm, or comfortable. It's not literal, but it fits the nature of hobbits well while referencing the "bag" in Baggins", and the connotations comes immediately in Norwegian without having try to deconstruct the name.
In this case, I think the newer "canonical" translation is generally considered unambiguously the best, but people often have favourite translations. E.g. my favourite Scandinavian translation of Walt Whitman's Leaves of Grass isn't even Norwegian, but an old Danish translation which sounds much "softer" (it's hard to explain)