I stumbled across an excellent audiobook of The Lord of the Rings…
It's better than any other I've heard before, and it's on par with BBC Radio's full-cast dramatization from 1980, keeping in mind the inherent differences between an audiobook and a radio play.
It's unlicensed/unofficial, it impersonates the character performances in the Peter Jackson films, and it uses Howard Shore's film score, so of course it's a violation of copyright on multiple levels and not available through normal channels. But if you don't care about that, you can get it here…