The IQ series stars Isaiah Quintabe, a brilliant young African-American man in LA who serves as an unofficial private eye. They are excellent.
The novels have dozens of characters with different accents and vocabularies. Sullivan Jones makes them come alive.
Jayne Entwhistle perfectly captures Flavia's gleeful and dangerous enthusiasm - especially when she is describing poisons in loving detail.
Dorothy L. Sayers. Whose Body? Narrated by Ian Carmichael. I don't think I need to explain who Sayers is. Carmichael played Lord Peter Wimsey on television and he doesn't so much read these books as perform them. Delightful.
Anthony Horowitz. The Word is Murder. Narrated by Rory Kinnear. Horowitz created Foyle's War and wrote many episodes of Midsomers Murders. In this series he is the narrator, and gets invited to serve as Watson to Daniel Hawthorne, a truly annoying ex-cop, now serving as a consultant to the police on difficult cases. The plots are truly mindboggling and Rory Kinnear does a good job of distinguishing between Anthony and Daniel.
And a few different experiences available from Libby...
Biggest surprise for me was Playback, which I had never read, because I had heard it was terrible. I enjoyed it more than The High Window.
Toby Stephens stars as Phillip Marlowe. I assume that, like him, the rest of the cast is British. But, boy, they have the accents perfect.
And one more I highly recommend, although it is not crime fiction.