I must honestly say that I forgot where I got this from, which is not a good thing. Thanks for pointing this out.
That said,
http://mashable.com/2009/06/07/blindsearch/ (apparently based on http://delicategeniusblog.com/?p=839) suggests that in a blind three-way test in 2009 both Yahoo's and Bing's results got picked as the best regularly (Google gets 41%, which is a substantial but not overwhelming advantage.) Note that that guy works for Microsoft, too.
That said, http://mashable.com/2009/06/07/blindsearch/ (apparently based on http://delicategeniusblog.com/?p=839) suggests that in a blind three-way test in 2009 both Yahoo's and Bing's results got picked as the best regularly (Google gets 41%, which is a substantial but not overwhelming advantage.) Note that that guy works for Microsoft, too.