Ublock Origin is an obvious one, but I also can’t stand not having Foxy Gestures anymore. It adds customizable mouse gestures, so you can set it up to have easy swipes to go back a page, reload a page, close a tab, etc, and it feels wonderful and smooth to use compared to just using the traditional buttons to do everything. Honestly it’s kinda wild to me that this isn’t more popular now that people are so used to phone gestures. It’s good for the same reasons!
LibRedirect Alternative open source frontends, very useful to survive on sites like Youtube, Twitter, Imgur etc.
Voat - Reddit Comments on YouTube & Web Pages Not so useful any more, but you can read what Reddit communities have to say about websites
Snowflake Fight cencorship