@WangthePhoenix
It all depends on what you're looking for! I'll list some stand-outs all the same that you can find on Mangadex. (using their scanlated titles)
"Onii-chan is Done For!" is an amazingly cute narrative about a dysfunctional early adult who is turned into a little girl by his genius little sister trying to give him a second chance at life. It has some early-installment weirdness (like the idea the latter has cameras installed in his room) or some cringe-y parts like the onsen episode's cliffhanger. But the cringe is the exception rather than the rule where it's at least 95% just refreshing and cute.
"Magical Trans" is refreshing just because it's about a boy who gets the ability to turn into a cute girl and he actually enjoys and explores it. Not just in the obvious lewd ways but really getting into enjoying the feminine social role with almost alarming enthusiasm. People have joked that the title might as well refer to the possibility they're a trans girl discovering who they are.
I hadn't read much of it but "My Girlfriend is a Real Man" is pretty funny and obviously it's the reverse of the standard, where it's a woman who becomes a hot guy and how her boyfriend copes with it.
Of course, sometimes the genre is more of a really tasty garnish rather than the point of the thing. Like "Fantasy Bishoujo Juniku Ojisan to" is a very well presented, written and funny parody isekai story that has humor that would actually hold up on its own even without a genderbent main character. But they do take that angle and run with it as well, finding a nice middleground between the story revolving around their gender situation and it being almost irrelevant.
And finally "Akuyaku Reijou Tensei Oji-san" is a very professional work by the Zoids mangaka that explores a really funny idea -- what if a very polite, mild-mannered late middle-aged salaryman became a villainess in an otome game? And... somehow, his gentle and conservative mannerisms make him the ideal lady?! And how can the story adapt to a villainess without a mean bone in her body?
I hope one of those works for you!