Firefox is my go to browser. It is the only opensource beacon to fight for browser engine diversity. It also boasts a lot of privacy controls.
Here are my top favorite add-ons for Firefox that I always use when I setup Firefox and recommend anyone to use.
This is a must have for me as it blocks the ads and clears all the clutter (hides the spaces ads take up).
This add-on remove tracking links in most of the urls, good to use in tandem with uBlock origin.
This disables WebRTC and stops WebRTC leaking your IP address to the web.
If you use Google for searches but don't want google tracking your search activity but still want to be logged into Gmail, Youtube and other Google services, use this.
This addon stops tracking by CDN and redirects CDN requests to your local CDN.