Obviously I don't know if everyone likes wikipedia, but I think it is fantastic. People submit articles on every conceivable topic and while the information is not infallible, it is certainly very helpful. Anyone is allowed to submit an article - not everyone is happy about this, because many people may question whether the articles conform to an acceptable standard. For this reason, many articles contain a proviso along the lines of 'this article may require cleanup to conform to wikipedia standards'. The fact that any article can be edited by anyone is in a sense a double-edged sword - on the plus side, it means that poor quality articles or articles with glaring factual errors are able to be improved. On the minus side, it means that the content of an article could end up bearing little resemblance to the article that the author actually wrote.
Wikipedia is an online encyclopaedia, and as such differs considerably from a traditional encyclopaedia. For one thing, wikipedia dwells in the land of the internet - a fickle and transient world in which words appear and disappear in the blink of an eye. Some will argue that a traditional encyclopaedia is inherently more permanent and hence a more reliable source of information. Nevertheless, this is one of wikipedia's strengths - articles of a topical nature can be created at the drop of a hat, while the information in a traditional encyclopaedia may be out of date by the time it goes to print. If you have absolutely no knowledge on a subject, then wikipedia is a valid starting point, and perhaps an end in itself. I personally find value in both wikipedia and traditional encyclopaedias; if you read one, then reading the other is like getting a second opinion. In any event, wikipedia is a useful tool for shedding light on a specific subject, as its name suggests.