You write "I want to learn a new programming language, or continue learning one I started in school, something that will compensate for the lack of algorithms in my work" If that is all you want, almost any language will do. Maybe, you want to take on a new one every month or so for a while to get a broader view on what's out there. Your experience, it seems, is only with Algol :-), so I would pick something differen…
I guess my itch is the fact that at work I do the same thing almost every day (make them websites, add guest checkout, style the page, integrate X and Y's API). It's becoming tedious and boring. I think my learning curve is now flat. I need some new challenges from which I can learn new stuff, use more math and elegant algorithms.
This is why I think I will be going to make some small games (monogame & C#, js)... and after I learn JS properly, I will definitely try some functional languages (Haskell). I think this will make me better at programming and help me see things from a different point of view... and most of all, have fun doing new things.