Laura Lee Hope: the Bobbsey Twins series
Carolyn Keene: the Nancy Drew series
Franklin W Dixon: the Hardy Boys series
Victor Appleton II: the Tom Swift series
Agatha Christie: the Miss Marple novels
Agatha Christie: the later Tommy & Tuppence novels
Dorothy L Sayers: the Lord Peter Wimsey novels
Leslie Charteris: the Saint novels
Ralph McInerny: the Father Dowling Mysteries
Ralph McInerny: the Notre Dame Mysteries
Jessica Fletcher & Donald Bain: the Murder She Wrote series of books
Lee Goldberg: the Diagnosis Murder books
Val McDermid: Lindsay Gordon novels
Val McDermid: the Tony Hill novels
Ellis Peters: the Cadfael novels
Gillian Linscott: the Nell Bray novels
GK Chesterton: the Father Brown stories
Elizabeth Peters: the Amelia Peabody novels
Elly Griffiths: the Ruth Galloway novels
James Runcie: the Sidney Chambers novels (upon which the Grantchester TV series is based)
Tamar Myers: the Pennsylvania Dutch novels
Jonathan Kellerman: the Alex Delaware novels
Charles Todd: the Bess Crawford novels
Hank Phillippi Ryan: the Jane Ryland novels
James W. Ziskin: the Ellie Stone novels
Dick and Felix Francis novels
Vicki Delany novels – various series
MC Beaton: the Agatha Raisin books (she starts out as a sleuth, then becomes a professional PI)
The Persuaders TV series
Hart to Hart TV series
Murder She Wrote TV series
Diagnosis Murder TV series
Jonathan Creek TV series
The Doctor Blake TV series