DuckDuckGo
What sets DuckDuckGo apart from the rest is its attention to user privacy. The search engine does not store your search queries and does not track your movements like Google does.
This means that you can comfortably search for what you are looking for without feeling like someone is tracking you.
It also means that your results are not biased in any way. And that you get generally the best results for your query, no matter who you are.
However, it should be noted that it doesn't have as many features as Google does. And that includes safe search and so on. It also shows ads, but it is based solely on your search query and has nothing to do with you personally.
Features: Privacy, impressive results
Cons: Fewer features than Google
Website: duckduckgo.com