Invidious
Invidious is a youtube proxy that cares about your privacy, and comes with extra features such as being able to download youtube videos and highlight youtube comments. It's very useful if you are using public Wi-Fi and YouTube is banned there. Proxy videos will turn on automatically, but to do it manually, just click on the gear icon in the top left corner next to "LOG IN", then check the box left of "Proxy Videos." If yewtu.be gets blocked, be sure to click the jet icon under any video, to see the list of instances.
Nitter
Nitter is another proxy, but for Twitter. If you're poor and have a slow computer, or if you don't want to sign up, you can browse Nitter to bypass that to get a faster experience. It also works as a data saver, as the dev's donation page verifies that it is only 58KB compared to Twitter's whopping 784KB for a single page.
16 Colors
16colo.rs is a gallery of ASCII artwork and demo files that go all the way back to 1990 Usenet boards. I'm not that fond of that sort of retro stuff, but to others that could be very interesting.