Duck Duck Go claims respect of user privacy. Check their page: https://duckduckgo.com/privacy.html.
One great thing about duck is its high customization of search query. I actually only use it in Chrome, to set search engine for address bar. To set the default search engine in Chrome, go to preference -> basic -> manage search engine. If Duck Duck Go is not in the list (which is the usual case), add it by URL
http://duckduckgo.com/?q=%s&kp=-1&kl=us-enHere are more parameters you can try.