As an aside, whenever a new search engine comes out, or there is an update to an existing one (Bing, mostly), the test I always use is to search for "python" with no other search terms. If the results are dominated by articles about the animal (as was the case with Cuil a few years back) then the search engine and its weighting choices probably isn't a good fit for me, personally.
Google will increasingly give you better results the more you use it because of data-tracking and search personalization.
I don't know if DuckDuckGo solves this problem. It probably doesn't because the problem is driven by keyword searches and only exacerbated rather than created by advertising-centric filtering. I'm not even sure it can be solved. It's something I'd like to see tackled, though.
See Google's FAQ: https://developers.google.com/speed/public-dns/faq#privacy
Makes me feel much better about using their DNS.
My IP address requests a particular site form DNS, in theory that request could be recorded. Even if Google doesn't know that I'm at that IP (which they could have gotten from some other site I'm logged into (say Amazon)) they know that my particular ip address has requested certain sites. They can then serve ads to that IP based on context
For context, I find DDG's top-of-the-results-page "did you mean this foo or that foo" fairly reasonable most of the time.