I used Common Lisp as my primary language for 2015-2022 and Python for 2023. I've used a few other languages along the way, in parallel to my main effort: Rust, Ada, Python, C++.

I'll probably just use Python this year, so many things are "baked in" to the language that it's the most straightforward. Only downside really is performance, but if you need high performance compiled code for Advent of Code problems you've generally not solved the problem efficiently.

I used Haskell to solve AoC 2022, and in the midst of it I read lots comparisons to Lisp, which in turn turned me off Lisp. E.g. "why calculating is better than scheming".

I'd suppose this is because I have a strong bias to mathsy looking aesthetics.