Sherlock Holmes....makes brainy sexy. Sure he's a self described "high functioning sociopath", with no people skills; but he's brilliant, driven and dresses wonderfully. Dr. John Watson is not a patsy (not a sidekick - he's a partner); sharp, wry, worldly man of action who tolerates Sherlock's idiosyncrasies because he misses the adrenaline edge of combat and seeks meaning in a life after war. They are evenly matched although Sherlock draws the attention and enmity of their foes - Watson is a good second.
The writing is engaging, cheeky, smart and fast paced. It rolls current technology into the stream of consciousness. The looks of awe when Sherlock figures it out - and his amusement when he learns he's alone are priceless. The cinematography, costumes, lighting and use of text overlays to move the story along are well placed and impressive on their own.
But the intelligence of the show is its presumption in the interest of the watcher; therefore moving with alacrity, flexibility and certain undefinable element of charm missing from many US shows (the brilliant but cancelled Life with Damian Lewis excluded). I'm a US viewer lucky enough to have a friend in the UK - but this show should gain followers worldwide with the power to draw from the past literary works and latch onto the current to slingshot us into the future of TV - for thinking people.