Alan Lee's illustration for Fangorn Forest in 'The Lord of the Rings'. Of all the illustrated editions, his is the most true to Tolkein's vision. I once saw some originals of his illustrations in Cambridge and was amazed that they were drawn to the exact size of the page, rather than twice size as is usual.
From Alan Lee's sketchbook. One of my favorite artists! -- Kre http://www.dana-mad.ru/gal/images/Alan%20Lee/The%20Lord%20of%20the%20Rings%20Sketchbook/alan_lee_the%20lord%20of%20the%20rings_sketchbook_07_lothlorien01.jpg