Ralph Bakshi's Lord of the Rings movie was kind of a letdown, even back in the day — and it definitely doesn't stand up to Peter Jackson's masterpiece. But the movie did generate some fantastic concept art. Just check out this concept art from Barry Jackson.
According to a post over at Meathaus, this art comes from Unflitered, a 2008 art book that Ralph Bakshi and friends put out — but the chapter on Lord of the Rings was scrapped due to rights issues. Bakshi posted all of the pages from the scrapped chapter on his blog a while back, and they include some absolutely fantastic concept art.
Michael Ploog's Nazgul concept, plus two paintings by Ed Hirth