Elementary @ Wikipedia
Elementary @ IMDb

Sherlock Holmes, a former consultant to the British police is now living in today’s New York city. He’s just come out of rehab but very few people know that.
His family has hired a sober companion for him who’s supposed to stay 24/7 with him.
Her name is Dr. Joan Watson, a former surgeon who doesn’t practice medicine anymore.
Now he’s helping the NY police solving crimes.

This show got a lot of heat and hate before it even started. How dare these ruddy Yanks steal our Sherlock?
And yes, there already is a British Sherlock show that brought the character into the present time. And it’s brilliant, I love that show. But it’s only three friggin’ cases a year (of which – to be blunt – not all of them are interesting either). All in January and then eleven months nothing. It’s worse than Doctor Who!
The older one particular idea is the more often it has been remade. How many Robin Hoods have there been? So I try to judge the show on its own merits and not as a comparison to either the British show or the recent movies.

Taking Sherlock Holmes the original character as a base there are three major changes.
Firstly his time travel into today.
Secondly he’s an alien, he’s a legal alien, he’s an Englishman in New York. He’s played by Jonny Lee Miller (Hackers, Eli Stone).
Thirdly as you might have correctly deduced, Dr. Watson is a woman now. Her name is Joan and she’s played by Lucy Liu (Kill Bill, Ally McBeal).
But everything else is pretty much like you expect it from a Sherlock Holmes based story. Even Sir Arthur Conan Doyle’s Sherlock used cocaine and morphine as drugs. His relationship with Watson is still purely platonic (neither Miller nor Liu play to any shipper crowds out there) and Holmes himself is still an obnoxious jerk.

I like the show and I’ll continue watching it even when Sherlock hopefully returns from the dead in January.