I use the following ones (on Firefox), except for uBO the others are just for conveniency:
Bitwarden
Gesturefy (for some time from early 2021 to late 2022 I used to use Vivaldi as my primary browser and now if I'm using a mouse, not having gestures in a browser feels odd...)
LibRedirect
Plasma Integration
uBlock Origin (middle mode and with some additional lists)
User-Agent Switcher and Manager (if I find a site that says it doesn't work with Firefox).