Google of course but don't overlook that Yahoo had a few more unique visits in July over Google? I'm kind of curious if this isn't somehow an effect of the way I feel windows 8 drives the consumer towards bing and Yahoo.
I think both the search engines are popular. But Google is the major search engine. It's all up to you what you want to use.
Definitely Google is the search engine giant and its bigger than Yahoo. But in last July Yahoo beats Google in traffic 197 million people visited Yahoo's site and Google's sites received 192 million unique visitors. I don't think that the achievement is stable but Yahoo actually was never far behind.
I always get better results in Google, and with recent hummingbird, Google's search results get more improved.
there are no of reasons behind that.. google is more reliable it is easy to handle google is more user friendly than yahoo..