Google search engine is best in world. It is true friend of a researcher. Anything you want to know google will search quickly. Best feature of google is that it provide different platform for different topics like google scholar for researchers to search research papers, a very different platform for searching powerpoint presentation. Knowledge of books can be get from google books. Only drawback of google is that sometimes it does not works on slow connection while other search engine like bing works on slow connection. For me google is the best because my whole thesis is completed only because of google.