There are a couple I have in mind. Like many techies, I am a huge fan of RSS for content distribution and XMPP for federated communication.
The really niche one I like is S-expressions as a data format and configuration in place of json, yaml, toml, etc.
I am a big fan of Plaintext formats, although I wish markdown had a few more features like tables.
Basically smaller file sizes than JPEG at the same quality and it also automatically loads a lower quality version of the image before it loads a higher quality version instead of loading it pixel by pixel like an image would normally load. Google refuses to implement this tech into Chrome because they have their own avif format, which isn’t bad but significantly outclassed by JPEG-XL in nearly every conceivable metric. Mozilla also isn’t putting JPEG-XL into Firefox for whatever reason. If you want more detail, here’s an eight minute video about it.