The new one. It's written by Stephen Moffat as an idea of how to play Holmes in a current day setting. Holmes is effectively an abrasive, unlikable, brilliant, perceptive son of a bitch. Very modern in locale and paraphernalia, but still kind of... old fashioned in tone. Somehow. I never liked Dexter, Holmes is my current favourite sociopath.
And Garoth was hinting that there's a lot of homosexual tones. Which there is. Mostly played for laughs in the very early bits. After that, mostly forgotten, I guess. Never really noticed. Well, except for one notable character, he who cannot be named. Who is the campest mofo this side of Julian Clary.
Benedict Cumberbatch (my god, his name is just as unwieldy as his face) makes Holmes a very manic, addicted person, to Martin's much more everyman Watson. Also the other writer of the show plays Mycroft. Who is in MI-something or other.
The writers basically went in with the viewpoint of "we really love Holmes, and we love the old series, and most of the stuff that's been done, but it's all so very Victorian. Holmes can work as a current idea, and here's how. We aren't replacing the old Holmes, just showing another way to do it." It was very much an experiment that happily played out.