I’ve always tried to use the most anonymous search engine I can – i’m a privacy advocate and just don’t like the idea of big corporations tracking and recording me.
I used to use Scroogle until it’s demise – see: http://www.islandearth.com/articles/2012/2/22/scroogle-is-no-more.html
When that happened I started trying out ixquick and duckduckgo but they just didn’t quite cut it – ixquick was more relevant than duckduckgo but nowhere near as good as Google, and at times was very slow. Duckduckgo was just too USA oriented and I wanted UK relevance.
In the end I gave up using them and for a while went back to Google. I did make sure I was using https to connect securely, set do not track and made sure I deleted cookies on browser exit and didn’t allow 3rd party cookies just to lessen the tracking a little bit.
Recently I saw several articles in the press regarding Duckduckgo so I started given them another try and I was pleasently surprised – it was fast and relevant to the UK. It seems like they have really got their act together and I have now switched to them on all my devices, including iPhone where there is a downloadable app that you can use as a replacement browser to Safari.