Here are some I found:
(Most of these come from series, and I have more books from the series so let me know what you liked.)

King of the Hill
==Peggy owns a bookstore

Zack Walker

Jeeves and Wooster #1
==this is just comedy, not a mystery

Father Brown
==dramatized audio mystery series

Tommy and Tuppence
==cute series by Christie about young couple who solve mysteries together in the 1920s

Stephanie Plum
==heroine/detective is a bounty hunter

Hannah Swensen
==bakery mysteries complete with recipes!

The Good Husband of Zebra Drive
The Saturday Big Tent Wedding Party
==Books from the #1 Ladies Detective Agency series

No 1 Ladies Detective Agency
==this is the video of the first story - great intro to the characters

Benedict Cumberbatch Reads Sherlock Holmes
==These are not the original Arthur Conan Doyle stories, but 4 new ones

Nancy Drew - The Secret of the Old Clock
==This is the first in the series.
==I've got about 20 other Nancy Drew books

Miss Marple -- The Body in the Library
==a BBC radio play

The Killings at Kingfisher Hill
==a new Hercule Poirot novel (not by Agatha Christie, of course, she's dead) as text, not audio

Lord Peter Wimsey - Five Red Herrings
==first of a classic Brit cozy series from the 20s-30s

Tony Hillerman - Blessing Way
==first in the Leaphorn/Chee series

Rosemary & Thyme
==cozy series with gardening theme

The Red House Mystery by A.A. Milne
==who knew he wrote mysteries?

Phryne Fisher- Cocaine Blues
==Australian woman detective from the 20s

Rumpole of the Bailey
==British series from the 70s

Jessica Fletcher
==new stories, not from TV episodes

Mrs. Pargeter
==kind of like Miss Marple but modern