Cranford (& Return to Cranford) with the superb Judi Dench, Michael Gambon, Eileen Atkins, and Imelda Staunton ("Delores Umbridge" for Harry Potter fans). This is one of those rare occasions when the TV/Movie is as memorable as the original book.
Miss Marple - Joan Hickson; any Agatha Christie movie she is in is the best. According to Inspector Slack (Murder at the Vicarage) she is a "nice looking grey-haired cobra" who "slides about" and sticks to unexplained murders "like chewing-gum to a cat.
Joan Hickson was the Miss Marple starring in BBC series from 1984 - 1992 seasons - 8 years) Born in Northhampton Aug. 1906 - 1998 (I've been watching her on WETA lately and I can't say she's my favorite but I love all the Miss Marple movies)
Hercule Poirot (David Suchet) meets Miss Marple (Joan Hickson). This was for a charity event, sadly they would never meet for an episode, as of course these great Agatha Christie detectives were from different era's.