TOD:
I studied Spanish, German, and Japanese in middle school/high school.
I remember very little about Spanish, can read German and understand a bit of it, and never made much headway with Japanese.
Hindi I am picking up on. Don't speak it too well, but when I watch a Hindi film that has no subtitles, I can sometimes figure out what they are saying.
As for favorite languages to hear: Japanese and Hindi both sound beautiful to me, when spoken.