I never had a problem with Google results. The only problem i always have is when there is not enough content about a topic. These are the times when i try another search engine, but the results are often worse then. I make around 20k searches a year with Google and i know how to find stuff with it, if there is something to find.
Google is free and Bing/DDG/Yandex make nothing better that would make me switch. There is not really a problem to solve when it comes to find available stuff. Quora and Stack Overflow try to solve a problem Google isn't good at. Getting answers to stuff when there is nothing to find out there.
http://millionshort.com popped up a while back and I've actually found it incredibly useful, especially for any topics more likely to be found on little personal sites.
Google is free and Bing/DDG/Yandex make nothing better that would make me switch. There is not really a problem to solve when it comes to find available stuff. Quora and Stack Overflow try to solve a problem Google isn't good at. Getting answers to stuff when there is nothing to find out there.