It ought to come as no surprise to anyone that I adore Agatha Christie, Dorothy L Sayers, Josephine Tey, Ellis Peters, Patricia Wentworth, Carola Dunn, Margery Allingham, Georgette Heyer, and Dorothy Gilman.
I have read but don’t love PD James (too grim), Charles Todd (too creepy and also joyless), Laurie R King (thoroughly enjoyed the Mary Russell books up through Locked Rooms, after which I felt the quality took a nosedive, and I HATED the one non-Russell book of hers I read), Ngaio Marsh (too humorless), and Jill Paton Walsh (tries too hard to be Sayers, and fails).
(All this is entirely subjective, of course–please don’t take any of it as an objective statement about the quality of these writers.)
I would like to expand my mystery repertoire, but I’m always hesitant about trying new authors because one never knows when a mystery is going to leave you feeling like you need to scrub your soul. I find I don’t care for many modern “cozies,” as the gimmicks and repetitive nature wear on me. I have enjoyed some of the Cat Who books, but not enough to feel the need to pursue the entire series.
Along with sordidness and grimness, the one thing I absolutely loathe is amateur detectives who are absolute idiots and shouldn’t be allowed to go around unsupervised, much less solve mysteries (and their method of “solving” is usually “get myself trapped by the murderer because I did something really stupid”), and stories set during older eras with protagonists who have thoroughly modern mindsets.
Oh, I also enjoyed the Dido Kent Regency mysteries, but cannot take mysteries featuring actual Jane Austen characters, or Jane Austen herself. Personal taste.