21st century Sherlock Holmes and Doctor Watson, with sharp, unique characters and expert takes on subjects like Holmes' sexuality (he's portrayed as an asexual, self-proclaimed high functioning sociopath and is realistically outcast for his attitude) and Watson's military hero persona (he's back from Afghanistan) without reducing him to a bumbling fool going "What's this? I say, Holmes! A clue!" as the TV adaptions tend to.
It's smart and clever and really hard to describe without showing people it, but watch it and you'll be hooked.
Also, it's written by the excellent Stephen Moffat and Mark Gatiss, with Watson played by Hitchiker's Guide to the galaxy movie actor Freeman who played Arthur Dent.
Trailer here: http://www.youtube.com/watch?v=cSQq_bC5kIw