KC, I respectfully disagree with you about Jim Hutton. Much of the reason this series has a cult following is because of Hutton. He played Ellery as he was asked: occasionally absent minded with a little humor and a lot of intelligence and charm in a Jimmy Stewart-like way. I think he did that well. The scripts often didn't allow him to stretch out beyond that. And the relationship between Ellery and Inspector Queen was one of the best, most believable father-son relationships I have seen on TV.
I was disappointed that show co-creator William Link many years later criticized Hutton for being a little soft without enough drive. My response would be that they should have written the character differently if that was what they wanted. Hutton provided a charming, amiable screen presence not often seen with TV detectives. Later in the run, they tried to stretch Ellery's emotions and actions a little further, and wrote more compelling stories, but it was too late to save the show. Actually, no film version of Ellery matches the fictional character in the books, and even there, we see two different versions of Ellery over time.
I always considered Murder, She Wrote to be "Ellery Queen" in drag with many of the same writers and same producers. My good friend Tom Sawyer, who was the show runner for Murder, She Wrote, told me that they made Angela Lansbury a little more pro-active and spirited than Ellery was, with less humor in the show, and made the mysteries easier to solve, which was one thing they felt hurt the Queen series as the mysteries were often difficult to solve on that show. He left they needed to make those "corrections" to help sell the show, and considering the long run MSW had, it's hard to argue that point. But, I still like Hutton as Ellery, and I think he could have done more if asked... which they did do in later episodes, and I think he did fine with that when asked.
Check out my favorite two episodes: The Adventure of the Wary Witness and the pilot movie, and you'll see Hutton do a little more than in some of the other episodes.