For me it would be Princess Mononoke, which is also one of my favorite films, period. I really appreciate the maturity and nuance it brings to it's environmental themes, which have been done in many other films, but not as well.
For me it is Spirited Away, followed closely by Princess Mononoke. I watched the latter first and absolutely loved it, but Spirited Away has a little bit more of surreal feeling that made me absolutely love it even more.
Language is English but Japanese titles and short comments eg. “かわいい!” are allowed. This is because my Japanese is shit and thus I cannot moderate it effectively.
For me it is Spirited Away, followed closely by Princess Mononoke. I watched the latter first and absolutely loved it, but Spirited Away has a little bit more of surreal feeling that made me absolutely love it even more.
Both of them are incredible.