The British and US versions of the Harry Potter books provide an interesting comparison. The British one is read by Stephen Fry, who is an excellent voice actor. I don't know the name of the US narrator, who does a fine job of not sounding too American, but still doesn't quite reach Fry's mellifluousityTM. I found it amazing what a difference this makes to the atmosphere.
Librivox is on the far end of the scale, though - complete potluck. Some stuff is definitely being read by people whom the microphone loveth not. Still, gift horses and suchlike.
The US version was read by Jim Dale, who was born and grew up in England.
It's difficult for me to decide which version is better. Jim Dale's is based on the US versions of the HP books (a minus), but he is a more playful reader. He tries to give each character his/her own voice characterization that's a lot of fun considering the nature of HP books*. Stephen Fry does not do as much voice characterization/differentiation, but… it's so immensely
British as I think HP should be done.
The reader and his/her approach how to do an audiobook is immensely important to me. Herein lies a problem, as the reader is not heavily advertised, and his/her style is only revealed by listening in.
I believe that the reader should get equal billing to the author for the audio version of the book. And there should be proper and carefully selected audio samples. A lot of samples I tried are tedious to work through, as they are simply taken from the beginning (with intro music and intro narration) with very little actual text from the reader itself, and, since it's from the beginning, with very little dramatic embellishment. I don't think that publishing companies put much effort into advertising. Considering how expensive most audiobooks are that's bad service to us customers. I don't buy and don't listen to many audiobooks because it's so tedious finding out which book and reading is worth my money.
Even if you know the reader, it can be a bad reading. I have a version of Crichton's "Andromeda Strain" read by Chris Noth. I know him. I know he's a capable actor (that's usually a plus), but this reading is simply tedious. He doesn't do any character differentiation making it very hard to follow who's talking. At least he should do different characterization for general narration and another for speech. He's emphasizing the wrong parts all over -- he's making little side comments more important than the really important bits and pieces.
Then I have a version of "The Silence of the Lambs", in German, read by the lady who provide the German speaking voice for Jodie Foster. She mostly does a good job, but when it comes to English words and names, her pronunciation is atrocious. For instance, she doesn't know how to pronounce "precious" (which was left as is for the sequences with Buffalo Bill. There's no German word that can quite grasp the same meaning), so Buffalo Bill comes across too ridiculous.
*I'm not saying that this way to do an audio version is
the way to do one. It works for the HP books, but other books need other approaches. Some people like audiobooks where the reader keeps dramatization and emotion out. I, however, like that quite a bit. Ultimately I think that an audiobook is a different media than a book, and should be treated as such. I have numerous versions of "The Lord of the Rings", in both English and German, and a straight out reading sucks, no matter who does it. By far the two best versions are dramatized audio plays, with multiple actors. It's funny how the German audio play I have, done a long time before the movies, uses a very similar sequence of events as the Peter Jackson movies, different from the books. By contrast, the British one (it's a BBC radio dramatization) is completely different.