Yes, I thought Hickson was the best of all the Jane Marples. Helen Hayes was pretty good, too. They were both frail and slight and unashamedly old. I noticed that, while the TV shows were fairly close to the novels, the Hercule Poirot series did some real stretching, which was a shame because David Suchet was such a believable Belgian.
I kind of prefered the Basil Rathbone Holmes to Brett's because, let's face it, the Doyle short stories were so short of action or wit.
Turning the Holmes stories into pot boilers and portraying Watson as dumber than Captain Hastings may have been heresy but it made for better theater. The game's afoot.