English is my native language. I've read Harry Potter in 6 languages. It's my go-to when I'm learning a new language.
If possible to find and not exorbitantly expensive I will try to read it the original language if it's Chinese or Japanese. Chinese sounds like a 5 year old wrote it when it's translated into English. Japanese sounds naked and too... IDK how to describe it? Both languages have more... subtext(?) or artfulness to how it's written. Japanese imo is the most technical of the languages I've read and it is almost impossible to translate.
Korean it depends. It's very hard to translate nuances into English as we don't have linguistic or social analogs. Most translators don't bother.
Spanish and Italian I've noticed some words that don't have sisters but in the few books I've compared seem close enough? TBH I'm not good enough at either to read anything difficult and don't know anyone that reads a lot in either language.