DuckDuckGo is a search engine I (/who/astynax) use daily on all my devices. Even if I need to "google" something I prefer to use the !g bang (see below) than Google itself.
The DDG's bangs is just a "killer feature" for me. I feel more comfortable to remember some bangs (a dozen at least) than to set up many custom "searches" in all browsers I have. Here are some examples I found useful:
!gi- Google Image search!wen- search over English Wikipedia!gh- search over GitHub!hackage- search over /Haskell packages!python- search over /Python docs!pypi- search over Python packages!define- search for word's definitions
Just because it faster (the search page is pretty lightweight) and more private.