There are lots of Search Engines are there in the market. But Google was and is the best Search Engine over the internet till date. It has more than 80% of market share in US over other search engines.
Microsoft launched Bing, but it is still at bottom 5 list of top search engines. I personally never liked Bing too. Once upon a time Lycos was very famous but Google just killed it!
Yahoo Search Engine also plays an important role to make our search easier by serving better results. But then also it just covers 6% approx. of total queries search over the internet amongst all search engines. Baidu from China is now becoming popular too, because it's widely used in China.
Here is the image which shows why Google Search Engine is at it's best.
Image Source: http://economictimes.indiatimes.com