I'm a big proponent for online privacy so thought I'd share my top 5 privacy focused browser addons. I have tried to keep these addons user friendly (low impact to daily browsing) to encourage a higher rate of adoption. These addons are very much set and forget.
Decentraleyes
Websites have increasingly begun to rely much more on large third-parties for content delivery. Canceling requests for ads or trackers is usually without issue, however blocking actual content, not unexpectedly, breaks pages. The aim of this add-on is to cut-out the middleman by providing lightning speed delivery of local (bundled) files to improve online privacy.
• Protects privacy by evading large delivery networks that claim to offer free services.
• Complements regular blockers such as uBlock Origin (recommended), Adblock Plus, et al.
• Works directly out of the box; absolutely no prior configuration required.
HTTPS Everywhere
Many sites on the web offer some limited support for encryption over HTTPS, but make it difficult to use. For instance, they may default to unencrypted HTTP, or fill encrypted pages with links that go back to the unencrypted site.
The HTTPS Everywhere extension fixes these problems by rewriting all requests to these sites to HTTPS.
uBlock Origin
An efficient blocker: easy on memory and CPU footprint, and yet can load and enforce thousands more filters than other popular blockers out there.
Privacy Badger
Privacy Badger blocks spying ads and invisible trackers. It's there to ensure that companies can't track your browsing without your consent.
Privacy Settings (FF Only)
Alter Firefox's built-in privacy settings easily with a toolbar panel.
Privacy setting can be configured automatically through the interface but as some of these settings can impact site use I would make sure you know what your turning off first. Google is your friend :)
Download:
Firefox
Let me know in the comments your suggestions or top 5.