I have to agree about Johnny Dollar. Bobson Blackie is a close second and I like Nero Wolfe quite well. It took a little getting used to Sidney Greenstreet’s voice; as it does not exactly match the image I have of Wolfe from reading the books.
I also like Gerald Mohr as Philip Marlowe.
I've actually read all the Mike Shayne detective books. That was a trip. The early ones were pretty good I thought, later becoming formulaic (and Davis Dresser, a.k.a Brett Halladay, actually franchised out his pen name for other authors to write Mike Shayne novels toward the end of the run). Jeff Chandler played Shayne on a radio series, and a few episodes are available in circulation.
As far as I know Johnny Dollar was limited to radio only. No books, movies or TV that of which I am aware. There was one reference to JD in the Marilyn Monroe movie, the Seven Year Itch, "His name's not Kruhulik. He's a private eye named Johnny Dollar."