My mother really enjoyed most of the Ellery Queen books. I didn't care for the ones I tried. She's more interested in the puzzle side than I am. In the ones I read, the titular detective felt to me like a hole in the story in as much as I didn't get an impression of him as a human being. The people around him had quirks and motivations and secrets. He was more of a space for readers to stand while looking around. There were, in the stories I read, a lot of long sections in which neither Ellery or his father (a police detective of some high rank) appeared even as observers.

The characters getting the most attention and development tended to be the one off characters who were there for one story only.

I think I reacted to the stories as if they were Nero Wolfe mysteries that had met some sort of literary vampire that drained out all of the bits that I enjoyed. You might like these, though. I'm not sure what you read mysteries for.

I remember watching a TV adaptation in the late 1970s with my mother, sister, and stepfather. I liked that, but I can't tell how much of that is that watching TV at all was a huge Event. I think this may have been the first prime time TV show that my mother let us watch (The Muppet Show was the second), and she thought it was important enough for all of us to watch it.