Honestly, Murder, she wrote was my least favorite role for the Dame, but it's the one all the obits are running with.
Hated the show, loved the conspiracy theory that Jessica is the real killer, and Cabot Cove had more corpses than Sunnydale.
That being said, Twelve FULL seasons is nothing to sneeze at, when seasons now top out at eight episodes, the Dame was pushing 22!
Also, interesting that she took a break in the middle of her own show, providing bookends for many episodes. When she got a production credit, she came back to the series. I'm glad she was able to get that EP credit, after all, it was her dang show.
I've heard she's particularly sinister in Manchurian Candidate, I'll have to give that one a watch.
I highly recommend pulling up her wikipedia entry, it is a hell of a read.