SQLite includes an extension to deal with JSON, and the command shell can also deal with CSV, and I also wrote a JSON parser in PostScript, so that means it can easily be used with PostScript codes too now, and of course JavaScript also has JSON built-in.
If it's human-readable, read-only, and almost completely unstructured, plaintext.
If it's human-readable, read-only, and structured but formatting doesn't matter, HTML.
If it's human-readable, read-only, and formatting matters, PDF.
If it's intended for humans to read and write via hand-editing, and then subsequently have a machine work with, then TOML. (Never YAML.)
If it's fundamentally tabular, CSV. (Never XLS.)
If it's an API result from a web API, reluctantly JSON; as much as I'd prefer TOML, JSON is more universal.
xml is too wordy
yaml, well I don't like indentation based formats, hard to see clearly