Why even ask the question? By far google is the superior search engine on so many levels. I'll name one reason that dominates all other search engines... Their algorithm.
It's not who is best, but who gets used more, and estimates range as high as 70% or more for searchers using Google. Yahoo and MSN (Bing) traffic is nice, but go for the low lying fruit first.
I have always used google, it probably just because i used to that more than anythiing although they are the king of search
Google is popular, and the best search engine, because it delivers the best results, and the best user experience.