Just tested the results on Google and Bing for something that randomly popped into my mind: "Konami Code".
Both gave me the relevant wikipedia article as first hit, so far so good.
Second and third hits on Google were a list of Games known to react to the code, and a page dedicated to collecting Konami Code easter eggs on the web. Good, relevant results.
Bing returned, as second hit, someone's facebook profile (Erm...no thanks), and as third hit, and I kid you not, someones MySpace profile (seriously, WTF?)
Google wins this, admittedly non representative, test hands down.