Lisp.
It just feels extremely natural to me, so it’s difficult to pinpoint specific features I like. But two such features stand out: the parantheses-based syntax and the extreme interactivity.
Perl. Its installed everywhere I need to run it and stuff I wrote over 20 years ago is still doing exactly what it should.
You’ll be damned if you ever need to know what exactly you made it do 20 years ago though as Perl is a write-only language ;p
That’s the joke, but it’s really not true.
You can write unintelligable code in most languages.
Perl’s syntax is fine, and you can write beautiful code with it - but it will also let you write fugly code that works.
I think those who say this seriously just don’t understand Perl, or even programming generally. (Whilst I like Perl, I’m also proficient in C, Java, JS, Python, PHP, Bash and probably a few more, so I’m not just promoting the only thing I know.)