Today I had to setup 3 Firefox profiles, because I started a new job, and I realized I never documented which extensions I use or why, so I had to work a little from memory. Hence, this post, which I plan to keep up-to-date as much as possible.
A little bit of rationale first. I'm very privacy-conscious, but at the same time very pragmatic. I use several profiles to add an extra level of data isolation. That also allows me to have different sets of extensions, because some are some intrusive that they break some non-important sites' functionality.
Finally, the list, in no particular order:
FlashGot, by Giorgio Maone: Better downloads handling.
Go-Mobile, by 'Geek in Training': A lot of sites are actually more useful (read, with less crap on them) in their Mobile versions. This plugins lets you switch from one to the other.
HTTPS everywhere, by EFF: Don't navigate in the clear anymore.
No Script, also by Giorgio Maone: A broad spectrum antibiotic. Not loading JS makes pages less CPU intensive, plus sites cannot track you if you don't make requests, plus also blocks videos.
Privacy Badger, also by EFF: In their own words, “protects privacy by blocking spying ads and invisible trackers”.
Tab Auto Reload, by 'Schuzak': I use this to reload sites that constantly log you out, but only under certain circumstances.
Tab mix plus, by 'onemen': Once upon a time ffox didn't have session management/recovery. Now it does, but not very good; I still think TMP's ones are better. Also, duplicate tab.
Toggle animated GIFs, by Simon Lindholm: Stop annoying animations. Just make sure to tick 'Pause GIFs by default'.
uBlock Origin, by Raymond Hill: an (ad) blocker, goodbye-adiós 15s ad videos in youtube.
So that's it. Unluckily there's nothing against browser fingerprinting yet (and my browser ranks as quite unique), and I don't know how much can be/has been implemented by [Mozilla]. If you have other suggestions about plugins, please do in the comments below. As I said, I'll try to keep this post up to date.
 I used to use ABP, but it seems it became a protection scam.