If you liked the Bruce Willis / Cybil Shepherd vehicle Moonlighting, you'll probably like The Adventures of Sam Spade , starring Howard Duff as Dashiell Hammett's most famous character. Like that witty detective show, Spade has no problem doling out the one-liners and occasional groaner double entendres opposite a bunch of Effie's as his dizzy secretary (Bewitched's 2nd Gladys Kravits played her, as did Lurene Tuttle) as he dictates the week's casebook. Each 'caper', as he calls them, usually features at least one sultry female and several no-goodnik thugs out to seduce and beat up our hero.
If you like your detectives a little more serious, try The Adventures of Phillip Marlowe . The series began in 1947 as being voiced by Van Heflin, who left it after six episodes to concentrate on his Hollywood career. He was replaced quite effectively by Gerald Mohr, a prolific actor in various other radio dramas. The writing, based on many Raymond Chandler potboilers, is pretty good, tough and smart. There's a noirish quality here that makes you hungry for the real thing, and thankfully, archive.org's public domain movie section has a whole directory devoted to like-minded thrillers and detective stories like D.O.A., He Walked By Night, The Stranger, The Hitch-Hiker, and the Heflin/Barbara Stanwyck classic, The Strange Love of Martha Ivers.