Sherlock: The Sign of Three (2014 Colm McCarthy)

Enormously enjoyable episode written with real warmth for its characters by Steve Thompson, Mark Gatiss and Steven Moffat in which Holmes attends Watson's wedding and recounts various stories in his speech, including a hilarious stag night, and a series of Conan Doyle-ish adventures such as the Poisoning Giant and - the biggest joke of the series - The Elephant in the Room.