Alexa.com
Note that this is all directional and the data is based on toolbar usage.
These sites that show stats data for sites are off by a lot - I've seen the analytics of big websites & medium sized sites and they're not even remotely close. Sometimes over evaluating and most of the time, completely under.
The countries almost always skew too heavily in Asia, because users with the toolbar installed tend to be from Asian countries - so you get a lot of overeporting as if India is the top country for every site.