As a songwriter I pay REALLY close attention to lyrics. If a song has crappy lyrics it loses all power for me.
One song I always have trouble remembering the lyrics for is "Babyface". The changing lines after "babyface babyface..." always catch me off guard. I never remember which line it is (lace / case / tin foil hair / outer space etc.).
Astonishingly, I remember all the lyrics to Numb.