I'll have to say Google. I heard someone say that smart people use Google and the opposite use Yahoo. LOL!
smart people don't always do the right thing... sometimes I use bing.com, because I'm just that kind of person
So far googles been leading the way for "search". Its why most use other products, like google chrome etc.
I have used many search engines but found Google the best of all. Because it gives the best results on SERP.
Most of the times I am using Google, but I do not love them any more, they did not removed videos from Youtube in respect of Last Prophet Muhammad Peace Be Upon Him. I will prefer all to sign a petition and force Google to remove video from Youtube.
I wouldn't go so far as to say that. If smart people only use Google, then there's got to a be millions of smart people out there. LOL. Google is the most widely-used. It's like second nature to use that now, but I still use Yahoo from time to time. Have a good day!