Of the dozens of actors to take on the role in the over a century since, a few have been truly outstanding, like Basil Rathbone, to whom the highly entertaining cycle of Holmes films in the 1930s and '40s owe nearly everything. Jeremy Brett's portrayal of the character on British TV starting in 1984 is widely considered definitive -- Brett researched the canonical Holmes meticulously to that end. So I don't mean it as a slight to either Rathbone or Brett or anyone else who's played the iconic detective when I say that the greatest performance as Sherlock Holmes is in fact that of Benedict Cumberbatch, star of the BBC's "Sherlock," the second series finale of which aired here in the United States last night.
Fortunately, Moffat and Gatiss' "Sherlock" is carried off with remarkable skill, with every creative level of the show combining holistically to create a vivid portrait of Sherlock Holmes as a fully developed person, and not just a bundle of costume choices and famous phrases. Not to downplay the excellence of Cumberbatch's work, but great performances don't exist on an island. "Sherlock" is constructed so that the audience sees what Holmes sees, with creative use of camerawork, editing and computer-generated effects. Even establishing shots are selectively blurred to pull focus to one particular area of the shot, as a nod to Holmes' powers of observation.
As for Cumberbatch's performance, his physicality is a delight -- he alternates between furious activity and catatonic stillness, seeming to be in motion even when still and to exist in a series of meticulously constructed tableaux when in motion. His Holmes is introduced to Martin Freeman's Watson as a potential flatmate, and proceeds to do an eerily accurate (and signaturely Holmesian) job of sizing Watson up based on a handful of physical details, with the ironic capper of mistaking “Harry” for Watson's brother, when in fact it's short for Harriet. Cumberbatch's Holmes explodes forth with extremely rapid bursts of text when itemizing his observations, his tone an exquisite mix of rigorously academic precision, dry wit, and an almost sensual pleasure in the befuddled awe on the faces of his audiences.
His chemistry with Freeman is also noteworthy; with the latter giving a true supporting performance as well as the odd timely reminder to Holmes that there are other people in the world, people whose value extends beyond being an audience for the detective's brilliance.
The way Cumberbatch handles these reminders is one of Sherlock's better running jokes, as he always has some tiny pause or facial twitch to indicate that the moment has registered. And he does learn from these reminders, building to a beautiful blip of a moment in last night's episode, “The Reichenbach Fall”: after Holmes is arrested, Watson gets himself arrested as well as a sign of solidarity, and for the briefest moment, the corner of Cumberbatch's mouth twitches. It's a subtle gesture that revealed that, for all Holmes' belittling Watson's intellect and personal life, he genuinely loves his friend -- and all in the blink of an eye.