Privacy Badger - blocks trackers, rewrites some tracking URLs, etc.
Multi-Account Containers - for those places where you want to keep tabs separate, giving each container its own cookies/session/etc.
Consent-O-Matic - automatically handles a lot of pages that shove annoying (and often technically GDPR-illegal due to lacking a quick "reject all" button) consent forms in your face.
Imagus - shows linked images on hover, including support for galleries and scrolling through all the images contained.
FYI- I was about to install "I don't care about cookies" when I noticed all the 1 star reviews. People saying its been purchased by Avast and is now data mining.
"I still don't care about cookies" is a community fork, does the same thing but isn't owned by a big company.