See Programming Languages I've Learned (more-or-less in order) [Update].
This came up on Twitter and Fosstodon.
See https://fosstodon.org/@vpavlyshyn/109908255464181943 and https://fosstodon.org/@slott56/109908527412493172.
I omitted a few things from the list because -- well -- there are a LOT of languages.
For example, in the 90's I got really good at using Awk. Just before I learned Perl, which (at the time) was almost -- but not quite -- better.
Recently, I've grown to like Gherkin at lot. See https://cucumber.io/docs/gherkin/reference/. The language is sometimes called cucumber, but that's incorrect. Cucumber is one (of many) tools that process Gherkin.
I also need to add Markdown, ReStructuredText, and LaTeX to the long list of markup languages I know.
I should probably extract JSON, YAML, and TOML into a separate category. They don't properly qualify as markup languages.
What's central here is the idea of choosing a single language.
The question shows up: "What's the most important programming language that will land me a job?" Or "... land me a better job?"
I remember -- back in the 70's -- being told that programming languages come and go. That's why the undergrad CS degree program only requires a few 1-credit courses in a language. They were considered far, far less important that data structures and algorithms, which really are timeless and eternal features of computing.
It's still true.
Some hiring managers look for folks with specific technical skills, as if that matters.
Smarter hiring managers look for folks who learn skills quickly, are quick to adapt, and share their knowledge widely.