Billy Wilder's The Private Life of Sherlock Holmes (1970) is his personal Magnificent Ambersons. It was taken away and edited without his supervision or approval, and the excised footage is currently thought to be lost. He apparently hated the version that was eventually released, but it's still a very enjoyable movie, full of typically bracing Billy Wilder humor (co-written, of course, with I.A.L. Diamond). The film was originally supposed to contain four unrelated stories and now contains only two. In the first one, Holmes pretends to be in a gay relationship with Watson to avoid the unwanted attentions of a female suitor. In the second, main section, he searches for a missing husband, and the search includes a visit from his brother Mycroft (Christopher Lee, a former Sherlock himself) and an encounter with the Loch Ness Monster.
This is the movie in which Holmes falls in love and -- unlike in the earlier Basil Rathbone films -- drugs are mentioned. Stage actor Robert Stephens gives us a sly, funny Holmes, Colin Blakely is Watson, and Genevieve Page is the woman who melts Holmes' heart. Those who have seen Robert Downey Jr's badass new version of Holmes will probably find this one a bit on the slow and/or stagnant side, but it was an important step in the evolution of Holmes between Rathbone and Downey, and it's definitely an underrated Wilder gem.
The movie is afoot over at SlashControl.