Rex Stout is the best of the old school of mystery writers, and his Nero Wolfe stories are priceless. The story lines are good, characterizations are wonderful, and the banter between Wolfe and his assistant and narrator are greatly entertaining. I have read, and re-read, all of the Nero Wolfe mysteries, and is these qualities that keep me coming back.
If you want darkness and violence, then these aren't for you, but the story lines are good, characters are likeable, and the wit in his writing, and the banter between Wolfe and Archie Goodwin (his assistant and story narrator) make the stories a pleasure to read.
This is one of my favorites, along with Prisoner's Base, The Father Hunt, Too Many Women, The Golden Spiders, and The Rubber Band. Some are dated now, but that can be part of the charm. And all are clever and multifaceted, but it is the characters that make these stories great.