4) The Chimes of Midnight (2002)
Arguably the most celebrated story of Big Finish’s first flush, Robert Shearman’s festive chiller found the Eighth Doctor and Charley investigating a series of murders in a (possibly haunted) house on Christmas Eve 1906. An irresistibly spooky blend of Upstairs Downstairs and Sapphire & Steel, it may yet stand as the finest Doctor Who Christmas Special in any medium. (If only it hadn’t come out in February…)