the best concept cover of ayu was A BALLADS. (also RAINBOW, but well, this cover is classic) From album covers I adore GUILTY and FIVE one. There are too many singles covers I like, but I always was fan of INSPIRE and Bold&Delicious/Pride one.
but well remember there was (miss)understood cover
and Sunrise/Sunset ~LOVE is all~ horror
Colours cover is not thaaaat baaaad. Better than Love songs and LOVE again ones.