What is your favorite detective / mystery book series? And why?

I loved the Amazon series Bosch so if I ever get back into reading I might read his books by Michael Connolly I believe the author is. Saw two Jack Reacher movies that were okay so that’s also on maybe list.

Cannot go wrong with the classic collections of Sherlock Holmes by Sir Arthur Conan Doyle.

Have read all the Reacher books, he is great. Peter Ash is another loner, Reacher type. By Nick Petrie. My favorite is David Baldacci. He has several series , all are great. I did like all of jack Higgins books, although he has stopped writing I think. Daniel Silva, Michael Connelly, Christopher Reich all are good.

Philip Kerr's series of Bernie Gunther books are brilliant.

I crushed on Sherlock Holmes even before I knew what crushes were

Charles Todd's detective books

Now this is right up my alley:
I m on Reacher #20
David Baldacci - Most all of his
Connelly - Haller & Bosch
Louuse Penny - Inspector Gamache
Peter Grainger - DC Smith (british)
William Kent Krueger - Cork O'Connor
Brian Haig - Sean Drummond
Henning Mankell - Wallender

The Travis McGee series
by the late great John D. MacDonald

Original, interesting, fun.

The Hardy Boys. I've been reading those books since I was a pre-teen.

I like all the good ones but quit reading in my teens and i just watch them on tv now

I loved the late Robert B. Parker’s books about Spenser and Hawk. But I got used to the late Robert Urich playing Spenser so it’s been weird seeing other actors in the role. And I always thought Avery Brooks used just the right subtlety for Hawk.

For some reason ever since I was a child I would never give mystery books a chance. They seemed boring.
I did read some Nancy Drew books because the school library seemed to have hundrededs and I had read nearly everything else.
Lol guess those don't count.