There are, alas, many programming languages may fit the anti-TMTOWTDI paradigm. You may have a different language in mind when I say Language That Shall Not Be Named
; the one I was actually thinking of is interpreted, not compiled.
I learned Pascal in 1983, and at the time it was a huge improvement over BASIC -- I could write structured (read: non-spaghetti) code in a human-readable language that did most of what I wanted (the key exception being that I couldn't take the address of a variable on the stack). Learning Pascal made me a better programmer.
I cast off Pascal for C, however, finding it more powerful and more empowering -- and when my work in C led me to X11 and Xt, a whole new world of object-oriented programming was opened up to me. I don't recommend either of those languages today, but knowing them improved my code. The biggest changes to my programming since then were triggered by C++ and Perl5 -- both languages that allowed me to use built-in features to do things I already wanted to do, but easier. Hash-indexed variables, I'm looking at you: thank you.
Other languages I have worked with over the years (including SysV shell, FORTRAN, Lisp, and Python2) haven't ever caught my fancy like Perl did, but each in its own way colored my experience in ways that have improved my Perl code.