This is a very cool "search engine anonymizer" which may help determine, at least in part, which search engine really has the best results across a broad spectrum of searches and individual opinions:
http://blindsearch.fejus.com/
Linked from Slashdot comments on that article mouser mentioned.
And a link to the results after 8 weeks of testing:
http://delicategeniusblog.com/?p=839
Unfortunately those results are from more than a year and a half ago. I wonder if he would publish updated numbers...
Here's a video from March of last year with perhaps updated numbers:
http://www.youtube.com/watch?v=aJgx3LSxWN0 (warning: NSFW!)
Maybe we can all start using this for some real world searches for a bit and see what kind of results we get?

- Oshyan