Here are a few websites which i think are worth a visit atleast once.. I like these websites...
http://www.wikipedia.com (For all kind of information)
http://www.orkut.com (For getting to know people)
http://www.metacafe.com (For free videos)
http://www.mGinger.com (For free ads on your mobile)
http://www.masti4india.com (For free latest hindi songs)
There are many many more and i shall keep adding them as and when i remember.. So do keep coming back and check out this page for additions..