I can't find anything wrong with it.
It's been a particularly good decade for the Coens (if you forget and forgive Burn After Reading). Everyone is slapping the "mature" label on this latest effort, which though deserved, is like saying No Country For Old Men is a "western," and stopping there. Yes, but?
A Serious Man is also really funny. It's like you're watching emotional slapstick. And this thing I adore about the Coens - they cast these Norman Rockwell type faces who you instantly fall for.
As for maturity, it raises some interesting (sincere) questions about faith and doubt, and respects its audience enough not to hit it over the head with obvious answers or nonanswers.
If the litmus test of a great film is repeatability, then this one wins out - it's the only Awards-season contender I'd actually like to see again.
Where the Wild Things Are
Not really worth mentioning
Every other movie of 2009? and I saw a mass of them. Hopefully next year will be less boring.