Answer by Professional Japanese Teacher
Indeed “paafekuto (perfect)” is not the best way to say ‘perfect’ in Japanese. You can try the following:
Fujisan wa saikoo desu.
Mount Fuji is the best.
Fujisan wa sugoi desu.
Mount Fuji is awesome.
Although perfect can be translated as paafekuto or 完璧(かんぺき) kanpeki, it is not natural use either one. Saikoo or sugoi would sound more natural to a Japanese person. I hope you’ve enjoyed your climb.