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.
That’s probably the reason for this preference.
10°C for me means my PC doesn’t heat up the room enough and I need a heater. 32°F and I will be shoving my feet in the heater.