Rossetti was one of the great poets of all time, and while "Goblin Market" is (of course) her masterpiece, her shorter works are also lovely.
Also, formatting poetry in markdown's a right pain the ass, and god help me if I ever want to post an e e cummings poem.
Remember me when I am gone away,        Gone far away into the silent land;        When you can no more hold me by the hand, Nor I half turn to go yet turning stay. Remember me when no more day by day        You tell me of our future that you plann'd:        Only remember me; you understand It will be late to counsel then or pray. Yet if you should forget me for a while        And afterwards remember, do not grieve:        For if the darkness and corruption leave        A vestige of the thoughts that once I had, Better by far you should forget and smile        Than that you should remember and be sad.