I currently don't have 1 favorite there are so many really cool languages.
but here are 2 and some that have inspired me.
Common Lisp for sheer Technological prowess has some very advanced features that I dont see very often, runtime recompilation, code as data, data as code, debuggers, images, redefinition, macros , perf measuring, recompilation during errors to fix bugs etc… and has a algebraic syntax which can be nice.
D for general purpose, again has features that are not common, optional GC, C compiler, zero allocation c strings, Lowlevel purity, and can be as Fast/Faster than C, and as simple as python(in the base language obviously pythons packages make up for basically all of its flaws).
Languages that have inspired me not favorites but changed the way I think are APL, Factor, Scheme, Lobster, Unison, and Koka, I hope you enjoy the read if you check any of those out.
I currently don't have 1 favorite there are so many really cool languages. but here are 2 and some that have inspired me.