Yap warning!!!
I would choose manga.
Bc I feel like there are a lot more manga than manhwa. Also, u can take literally any topic and there's always a manga that fits it. It could be the most random and specific plot and somebody somewhere made a manga like that lol.
If not manga, I would choose manhwa bc I love that they're colored and especially when it comes to straight isekai stories, the artstyles are so scrumptious. And there are fairly good amount of different plots and characters in manhwa too so...
I'm sorry but I would choose manhua last. Compared to manga and manhwa, manhua usually have very few unique characters and tropes. Almost every manhua is very lighthearted and wholesome, and I don't usually enjoy very cheesy type of stories. And for some reason, I don't like most of manhua artstyles except for old black and white ones or very few colored ones like "little mushroom". Idk why but I get bored midway everytime I read a manhua. It's just not my thing.
manga ... And lets not lie There's better quality control when it comes to manga ... Because editors are taken seriously idk about manhwa/hua tho. How many times have you seen a series being dropped because the artist backed out due to overwork. When i love a novel i trust that the manga version would have good QC
Probably manga since it has so much variety you'll never get bored. I feel like most manhwa are kinda tropey they're like repetitions of each other with some tweaks. Also their art looks the same as well. Actually my favorite Chang Ge Xing is a manhua but it's rare to find good chinese to english translations and cohesive plotlines for some reason. Xia Da is just a god among manhuajias. But I do like cnovels better than japanese or korean light novels and their danmeis are definitely on another level.
If you can only, read from one of these categories, What would you pick , Manga or( manhwa/hua) and why?