Addons

Essential

uBlock Origin (with custom filters)
Stylish
Session Manager
GrabMyBooks
I don’t care about cookies
Clean Uninstall
New Tab override(since Firefox doesn’t allow setting newtab.url any more for some reason)
Suspend Tab (actually works, as opposed to UnloadTab)
VimFx(with custom mappings, don’t forget to back up)
wallabag(v2)
Warn Before Quit

Unused

UnloadTab (loses tabs, not recommended)
Super Start (load a custom html page from file:/// instead)
RSVP Reader
ScrapBook
HTML5 Video Everywhere! (works only sporadically)
Resurrect Pages
Tab Mix Plus
Random Agent Spoofer
Content Search X
BetterPrivacy
QuickMark
Privacy Badger (or Disconnect or Ghostery)
NoScript (even with javascript turned on, it still offers some security features)
Mozilla Archive Format
meta-q-override

misc

remove default mail providers
turn off sync, hello, pocket, tiles, weed out search providers, turn off telemetry etc.
set default search engine, disable search suggestions

browser.search.showOneOffButtons false (deprecated)
browser.newtab.url and browser.startup.homepage to about:blank(obsolete, see new tab override)
browser.pocket.enabled false
beacon.enabled false
browser.visited_color #00CCCC
dom.max_script_run_time 40
dom.max_chrome_script_run_time 40 (from 20)
dom.battery.enabled false (how could anyone think this was a good idea)
dom.event.clipboardevents.enabled false
general.warnOnAboutConfig false
geo.enabled false
network.dns.disablePrefetch true
pdfjs.disable true
plugins.enumerate_names (empty)
privacy.trackingprotection.enabled true
webgl.disabled true (will break fullscreen mode?)
browser.fullscreen.{animateUp,autohide}
dom.serviceWorkers.enabled false (what a dumb idea to let scripts run after closing a tab)
privacy.file_unique_origin=false - See CVE-2019-11730 But I don’t particularly care Needed so that file:// stuff works properly and doesn’t complain about CORS, e.g. for accessing cssRules
devtools.inspector.color-scheme-simulation.enabled=true for testing out prefers-color-scheme, see stackoverflow