Wikipedia - My Second favorite on web

In my opinion this is the second best thing happened to the Internet, first is ofcourse GOOGLE (to me). Every article is worth reading and I really like the way it has been organized.

And the most beautiful part is that anyone can play with it as it allows everyone, absolutely everyone online can edit and save the pages. So if you don't like something (you won't get that chance, believe me), edit and save the pages and see it online it. Even if you mess up something while editing, don't worry, Wikipedia guys will take care of it.

I appreciate the Usability of Wikipedia, it is very easy to use and understand. In my case, I don't actually search on it, I directly append the topic of interest in the end of the url: http://en.wikipedia.org/wiki/topic_name and go, if it is present on the site it will take me to the article or if it is related to some other topic, it will auto redirect to that topic, that is what I call simplicity.
For example, if I wish to read Usability stuff I will just type http://en.wikipedia.org/wiki/usability and I am on the page, if I want good material on web
usability, I will follow the same thing above but will just add underscore ('_') between the two words which will make my url look like: http://en.wikipedia.org/wiki/web_usability

Google and other major search engines loves it. I see atleast one listing from wikipedia in most of my searches.
Wikipedia Rocks!