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.
I wish standards were always open access. Not behind a 600 dollar paywall.
When it is paywalled I’m irritated it’s even called a standard.
DP >> HDMI