The Hyperion books by Dan Simmons. Hyperion has full cast, the rest doesn’t, but still very high quality narration.
Honourable mentions:
Alastair Reynolds and John Lee collaborations. Lee has the perfect voice and tone for Reynolds’ precise (and somewhat aloof) language.
Neil Gaiman books. Gaiman does his own narration, and I can’t imagine his books without his voice.
Dishonourable mention:
John Scalzi, read by Will Wright. Wright reads as if every line in Scalzi’s works was hillarious. Scalzi is a very funny writer, but his books have somber set pieces, and Wright ruins the immersion there.
The Hyperion books by Dan Simmons. Hyperion has full cast, the rest doesn’t, but still very high quality narration.
Honourable mentions:
Dishonourable mention: