I don't have enough evidence to prove this, but Patrice Chéreau's La reine Margot is probably the sexiest costume drama ever made. It's certainly the sexiest one I've ever seen. At points it practically drips with eroticism. That the film is also a tremendous tragedy would only be a surprise to anyone who doesn't know French history, but as that probably applies to most Americans, it's worth mentioning, especially since the last act is really, really great at it, and with all the sex and romance on display throughout the rest of the film, it's very easy to envision a version of this story that ends with at least a little happiness.
But, this being a French historical drama about the ruling class, it was never going to have a remotely happy ending.
I found it incredibly difficult to pick a best shot, narrowing it down to four, from which one singular shot simply wouldn't emerge. I would blindly point and pick one, but that would go against the whole concept of this series, so I had to sit here staring at my screen and thinking VERY. HARD. for quite a while in order to complete the task at hand. In the end, it came down to what I think the film is about, and which shot exemplifies that best. But first, the runner-ups.