[_jomo]

It's difficult to pick a single one.

uBlock Origin[0] is probably the one with biggest impact. I assume most of the HN folks know it, but It's a general purpose blocker that can block network requests and DOM content with support for AdBlock plus rules and host files. FilterLists[1] is a nice resource to find lists you can subscribe to.

I also like Privacy Settings[2] a lot. It's a GUI for changing all the built in features Firefox already has, allowing you to quickly switch options on and off as you like.

0: https://github.com/gorhill/uBlock/

1: https://filterlists.com/

2: https://github.com/schomery/privacy-settings/

[ApplaudPumice]

Yes, I was thinking about uBlock origin, but would an "average" user be comfortable with it? That's the problem.