unforgettable
US /ˌʌn.fɚˈɡet̬.ə.bəl/
UK /ˌʌn.fɚˈɡet̬.ə.bəl/

1.
inoubliable
impossible to forget; very memorable.
:
•
It was an unforgettable experience.
C'était une expérience inoubliable.
•
Her performance was truly unforgettable.
Sa performance était vraiment inoubliable.