Default to DuckDuckGo!
There are many advantages of not using Google as your primary search engine. Escaping incessant tracking across the Internet is just one such benefit. With the recent brouhaha about NSA tracking almost all of us via the PRISM program, it may be a good idea to do with less tracking around the Internet. A search engine we should all consider using instead of Google, is DuckDuckGo.
The USP of DuckDuckGo is that they don't store identifiable information about you along with the searches that you perform. Hence, even if the US Government wanted them to share data, they wouldn't have it! Yes, there is a compromise: they cannot provide you with the kind of personalized search results that Google can. However, for most generic searches, they'll do just fine.
I have personally been using DuckDuckGo for over an year now and the search results are just as great, if not better, than those that are returned by Google.
Most of us don't explicitly visit Search sites — search engines, these days, are usually integrated right into our browsers in the form of the search bar or the "Awesome Bar".
Here are a few easy steps that you can use to setup DuckDuckGo as your default search engine across all your browsers.
Firefox
To get DuckDuckGo on Firefox, it is as simple as installing the DuckDuckGo Plus addon and then explicitly selecting the DuckDuckGo search engine while carrying out a search.

Default to DuckDuckGo on Firefox
It is that simple!
Google Chrome
Yes Google Chrome does allow us to change the default search engine to something other than Google. The process is very simple.
Step 1: Using Google Chrome browser, visit http://www.duckduckgo.com and perform a search; any search will do.
Step 2: Now, open the settings page in Google Chrome and go to "Manage Search Engines".

Manage search engines on Google Chrome
Step 3: DuckDuckGo should appear in the "Other search engines" section. Just click on "Make default" against it, to make it the default search engine on Google Chrome.

Default to DuckDuckGo on Other Search Engines
You are done! Now, every time you search using Chrome, DuckDuckGo will be the search engine that is used.
Internet Explorer 8
Internet Explorer also handles search engines through addons.
Step 1: Click on Tools -> Manage Addons

Manage Addons on Internet Explorer
Step 2: In the "Manage Addons" screen, under the "Search Providers" section, click on the link "Find more search providers".

Find more search providers on Internet Explorer
Step 3: The Internet Explorer Gallery webpage should have opened up. Here, select the "search" section and select "DuckDuckGo for Internet Explorer".

Select DuckDuckGo from the Internet Explorer Gallery
Step 4: Add the DuckDuckGo addon to Internet Explorer.

Add the DuckDuckGo addon to Internet Explorer
Step 5: In the "Add Search Provider" dialog that opens up, confirm that you want to add the DuckDuckGo addon. You can also choose to make this your default search provider here.

Confirm the selection and make it your default
With this your browsers should be setup to use DuckDuckGo as the default browser. Enjoy your anonymous, unfiltered searches!