Honestly, I would advise to not pick a language based on popularity, hate, or whichever of those qualify as internet fame these days.

I would approach the question with what you want to get out of your toy project. Do you want to get something done? Then pick a language that is close to what you are already familiar with. Do you mainly want to learn something? Go with a language with concepts you are unfamiliar with, eg. pick a functional language if you mostly do OOP stuff or pick a low level language when you mostly do high level web stuff.

My advice, generally speaking, is: When you do something in your spare time, don’t spend it on things you already do at work. The way to improve in software development is to see problems from many different angles and to rethink the solutions you already know.