Dark Reader dims pages to make them easier to read. It doesn't seem to work as well on Android, though.
Decentraleyes decreases connections to CDNs so pages load faster.
uBlock Origin protects your browsing data from trackers and prevents many advertisements from appearing. For users of Pale Moon and its derivatives, eMatrix is also available.
Hardcore Gaming 101 mainly hosts reviews of old and obscure video games, although some recent games are covered, too. Be careful when browsing it; some documents contain spoilers for the games they detail. Old articles can be found on the official archive.