Lee's work is in a class of it's own. I doubt I would be able to vizualise lord of the rings etc without his artwork. It's so rich and adds to the whole middle earth atmosphere. Here are some of his hobbit artwork, I wonder if the movies have taken inspiration from his work.
http://tolkienilu.chez-alice.fr/epop..._porte_lee.jpg
http://tolkienilu.chez-alice.fr/epop..._troll_lee.jpg
http://tolkienilu.chez-alice.fr/epop..._smaug_lee.jpg
http://tolkienilu.chez-alice.fr/epop...arrock_lee.jpg