Google has been on top for quite a some time now as far as search engine market is concerned. According to the seoMoz, Nielson-Net, Alexa and other traffic analysis report, Google covers 87.6% of market share globally. Its nearest competitor is Bing having only 4.2% of market share.
More than 2 billion people hits Google per day in search of something worldwide.
As my other friends told, it's the most reliable search engine not only for us but worldwide.
Hope it'll help you