The Hound of the Baskervilles (1968)
Two part BBC production starring Peter Cushing as Sherlock Holmes and Nigel Stock as Dr. Watson.
Never straying far from the source material this is a beautifully atmospheric mood piece. Although you don't see much of the hound itself you hear it frequently baying in the moonlight sending chills down the viewer (and Watson's) spine.
Whilst it's not as slick as the Hammer version which also starred Cushing from ten years or so prior, i found this a delightfully almost comforting viewing experience perfect for these cold winter nights.
This was part of a second series of Holmes adventures for the BBC. Cushing playing the character this series after taking on the role from Douglas Wilmer.