Really interesting discussion!
Have to admit that there is a lot of junk out there passing as "entertainment". There is no doubt that from a Biblical perspective, the practice of witchcraft and the occult are sins. I think the question is "what is the message and how is it being preached to the audience"? Shows like Charmed and movies like Harry Potter are intended for the younger audience and to this younger audience it gives the impression that dabbling in the occult is cool - in fact, it can be used to defeat the Bad Guys. The elements of witchcraft are obvious - spells, wands, magical objects, magic potions etc. Clearly what is being promoted is the use of witchcraft and this is not the message that you want young impressionable children to be exposed to. As adults, you would hope that we would be more discerning as to how what we choose to take away from movies/shows that we watch. But there is no denying that many adults watch these movies like children, and so are easily swayed by the message.
I think Lord of the Rings is completely different altogether. If you have seen the movies, there is no chanting of spells, no magic potions. When do the heroes call upon supernatural dark forces for help? Even Gandalf doesn't wave a wand or chant prayers to the gods. Yes there is the ring, but the ring is possessed by an evil spirit and the main heroes (Sam, Frodo & Aragon) do not use magic to destroy it. In fact, the movies and (more importantly) the books promote a message of moral victory - we see this clearly in Sam and Frodo, and also in Aragon - against the forces of evil. If you read the whole back story to the LOTR saga, found in a book called the Silmarillion, you'll find that Tolkien wrote of a single Creator and the fall of his creation.
Anyhoo, I think the bottom line is - what is the message and how is it being preached to its intended audience? Even if the message is 'good', the way in which it is being communicated may corrupt the audience.
PS Excellent website Mr Shuttertalk