My list is similar: PDP-11 BASIC, followed quickly by UCSD Pascal, Turbo Pascal (which brought the most important parts of UCSD Pascal's IDE to CP/M-80/DOS), LI

My list is similar: PDP-11 BASIC, followed quickly by UCSD Pascal, Turbo Pascal (which brought the most important parts of UCSD Pascal's IDE to CP/M-80/DOS), LISP. And then Awk, and associative arrays. You can literally create any data structure you need using associative arrays. It won't be fast; but if I could have only one container type, this would be it. And then TCL, which is where I really learned to appreciate meta-programming. (I wrote Tcl's "Snit" object system in pure Tcl; it got quite a lot of use once upon a time.) I make it a point to check out new languages on a regular basis, just to keep myself fresh (most recently, Rust and Haskell).