YOU SAID:

this is the most fun I've ever had

INTO JAPANESE

これは私が今まで持っていた中で最も楽しいものです

BACK INTO ENGLISH

This is the most enjoyable thing I've ever had

INTO JAPANESE

これは私が今まで持っていた中で最も楽しいものです

BACK INTO ENGLISH

This is the most enjoyable thing I've ever had