I use Firefox. Other than Ublock Origin and Bitwarden, these are some of my favourites :

Temporary Containers is a new favourite of mine. It works just like container tabs, but the difference is that it deletes the history of that tab once it’s closed, similar to Incognito/Private instance.

Reddit Comments for Youtube - If a youtube video has been linked to reddit, then it basically gives a small box which lists all the subs the video has been linked to and shows you the comments. If you’re logged into reddit, then it will allow you to comment as well.

Keepa for Amazon. Let’s you track price history for any product, so you can see if a sale is actually a real sale or not.

Tab Session Manager - Basically lets you save tab sessions.

Enhancer for Youtube and Pockettube Subscription Manager - Gives various youtube enhancements.

Stylus - To style websites. I mainly use it to fix the youtube thumbnail and font size.

Battle of Wesnoth. Haven’t played it in a while, but I remember spending hours playing that at one point.