I've been using DuckDuckGo as my default search engine instead of Google for about 12 months. This is why I could never go back.
1. Privacy
The main reason I switched over in the first place was a privacy concern. Spawned from a talk by the irrepressible Aral Balkan, the notion of corporatocracy was first lodged in my brain. Google weren't just storing all my search history, but they were using it for all manner of things except for the one thing they assured me it was for; improving my searching.
With a Privacy Policy written in clear English, DuckDuckGo are all about you.
2. Quality of Search
Using Google you're subject to what is known as the filter bubble. The filter bubble is where your search results are conditioned by the history of your previous searches. That means that different results are shown to different people. Not everyone who searches for David Cameron (or guns) sees the same thing.
Taken from http://www.dontbubble.us - a lovely little explanation of the perils of the bubble loop
There is no filter bubble on DuckDuckGo. The ability to switch which local region you're searching in gives you more options and ultimately, a truer search.
3. Design
Look at it. Look how clean it is! Don't like how it looks, then head straight to part 4!
Lose the visual clutter of Google, and the mismatching styles and enter some gentle alignment and you get DuckDuckGo. Search for a topic like Airbnb and you'll get a tidy summary (from Wikipedia of course) at the top of the page, and some genuinely related links to the right. All of this in your search results.
Search for an HTML snippet like <td>, and you'll get an HTML table in correct syntax ready for you to copy and paste. Occasionally a StackOverflow answer will even appear up there!
4. Customisation
So you don't like how it looks and you prefer Google. Why?! Only joking.
You can change how DuckDuckGo both looks and behaves. You can change the default ProximaNova font to Helvetica Neue, or the colour to pink. You can change the way links open, or stop the favicons from displaying. You can truly cater it to your tastes.
5. Instant Search
You know how Google can give you the results to basic arithmetic, or tell you the weather without having to leave your search results? Well DuckDuckGo have been doing that for longer, and arguably, they do it better.
The weather is supplied by the wonderful and gorgeous Forecast.io, the clean strokes and bold lines are a breath of fresh air.
But perhaps the cleverest thing, is DuckDuckGo's ability to play a song from within the search results. Try it. You can play a Soundcloud tune without ever having to leave your search results.
Oh, and if you search for "Stopwatch" you get (you guessed it) a working stopwatch.
6. !bangs
But after all of this, you still can't help but miss Google.
Sometimes, you need Google; their image search or maps are unrivalled, both of which I still use daily. Don't fear though, DuckDuckGo have created !bangs. By simply appending "!google" or "!g" to the front of your search query and you will be transported back to the warming blanket of Google. If you type "!maps" then it'll take you to Google Maps - it's pretty clever stuff. It'll work with !wikipedia, or !stackoverflow, !verge, and so on and so on (4975 at the time of writing. Wow).
But the best part? DuckDuckGo does all of this anonymously, and if you don't know why that's a big deal (or if you don't care) then I implore you to watch Aral's talk below.
For a visual comparison of privacy at DuckDuckGo vs Google, check out this gorgeous infographic over at Opitlocal.org.
I hope you enjoyed this review of DuckDuckGo, but if not then please let me know in the comments!