Cat Who series by Lilian Jackson Braun. This series was started in 1966 - I discovered it back in 1987 when it was re-issued in paperback. I haven't read the series in several years so thought I would go back and listen to it on CD. It appears to be still going strong - makes you wonder if Braun actually writes this series anymore.

Cat Who Could Read Backwards
introduces Jim Qwilleran, a prizewinning reporter who's been on the skids but is now coming back with a job as feature writer (mostly on the art scene) for the Daily Fluxion. George Bonifield Mountclemens, the paper's credentialed art critic, writes almost invariably scathing, hurtful reviews of local shows; delivers his pieces by messenger; lives with his all-knowing cat Koko in a lushly furnished house in a moldering neighborhood, and has a raft of enemies all over town. He offers the newcomer a tiny apartment in his building at a nominal rent, and Qwilleran grabs it, surmising the deal will involve lots of cat-sitting.

Cat Who Ate Danish Modern
Qwill is given a new assignment from his editor is to produce a special Sunday supplement on interior decorating. For Qwilleran and his Siamese investigative cat, even interior decoration has its interesting side, murder for instance. Again Qwill is homeless but is able to sublet a wonderful modern apartment for free. He has all the luck. He finds Koko a female siamese named Yum Yum and develops a romantic interest but since Koko doesn't like her we know she won't last.

Cat Who Turned On and Off (1968)
Cat Who Saw Red (1986)
Cat Who Played Braums (1987)
Cat Who Played Post Office (1987)
Cat Who Knew Shakespeare (1988)
Cat Who Sniffed Glue (1988)
Cat Who Had 14 Tails [SS] (1988)
Cat Who Went Underground (1989)
Cat Who Talked to Ghosts (1990)
Cat Who Lived High (1990)
Cat Who Knew a Cardinal (1991)
Cat Who Moved a Mountain (1992)
Cat Who Wasn't There (1993)
Cat Who Went into the Closet (1994)
Cat Who Came to Breakfast (1994)
Cat Who Blew the Whistle (1995)
Cat Who Said Cheese (1996)
Cat Who Tailed a Thief (1998)
Cat Who Sang for the Birds (1998)
Cat Who Saw Stars (1999)
Cat Who Robbed a Bank (2000)
Cat Who Smelled a Rat (2001)
Cat Who Went Up the Creek (2002)
Short and Tall Tales (2002)
Cat Who Brought Down the House (2003)

Cat Who Talked Turkey
The shooting death of a well-dressed gentleman in the woods on Qwill's property is nearly neglected in the fuss and excitement engendered by the neighboring town of Brrr's bicentennial. On the trail of a story for the celebration, Qwill interviews Edythe Carroll, a wealthy widow who has retired to Ittibittiwassee Estates from the magnificent mansion she plans to leave to her granddaughter, Lish (short for Alicia). Little does Edythe know that Lish and her boyfriend, Lush, have already trashed the place. After dozing off in his gazebo after a busy day, Qwill is startled awake by strange noises, including some coming from Koko. Enter an entire family of wild turkeys. If this all sounds like a bit of a ramble, it's quite in keeping with the story, which wanders pleasantly around Moose County, surveying its eccentric citizens as they go about their idiosyncratic business. In spite of two murders and a pair of villains, the tale is as cozy as an hour spent cuddling your favorite cat.
Cat Who Went Bananas (2004)