Digital Inspiration has recently published an awesome map of the most visited websites in the wordl according to each country. The data was collected from Alexa rankings which is one of the most accurate ranking algorithm online. It is probably even better than Google Page rank.
This World Map of The Most visited websites shows the popular sites within each country. It is not suprising. though, to find Google reigns supreme in almost all of countries followed by Facebook and Yahoo. The only exception to this rule is China where Baidu is ranked number one. Baidu for Chinese is like Google for us.
This is a good resource to share with your students and let them learn about what other people in other countries browse the most.