clara or myne....
"Average Abilities" girl was really good, but I have to go with Iruma-kun. Shame about that one arc that really soured the mood. (What were they thinking?). The wrestling isekai was pretty great, too.
I don't know if Disgaea was really the one that invented the colorful demon teenager thing, but it's such a strong genre. We're experiencing again this season with sleepy girl and of course it's immensely popular for it.