Harry Potter is definately a no no, reading the books or watching the films. Its demonic and spiritistic.
Lord of the Rings is viewed as demonic. One elder really liked the Tolkien book as a child and watches it in secret so as not to stumble his wife and 3 daughters.
Star Wars was mentionned way back as spiritistic because of the way the Jedi use the Force. (I think a connection was made to the a false holy spirit).
Data the android from Star Trek: The Next Generation was viewed as a demon by one particular brother, due to his grey skin and lifeless yellow eyes.
Bible-based films such as The Passion of the Christ, The Greatest Story Ever Told or The Ten Commandments are "frowned upon", due to their being "Christendom's view" of the bible events.
Soap operas like Coronation Street, Eastenders and Hollyoaks (not sure how this one translates to our non-British friends) were mentioned on the platform once, as bad-association (allowing ourselves to keep company with people who cheat, lie and fornicate with each other, all just for a good story line. This "council" had the result that many soap-addicted sisters chose to give up their only weekly pleasure in life.
One sister was "stumbled" when an elder served alcohol at a "christian gathering". Since then, no alcoholic beverages have ever been served in any gathering organized by my congregation.
E.T., Fantasia, Jaws, The Matrix.... the list goes on and on and on and on....
Note that this is usually not official WTS doctrine, but they are often mentionned on the platform at certain meetings or even assemblies. It is often the opinion of one or two staunch members of the congregation who impose their opinions on others, but it is presented in the guise of denying yourself something because it might stumble others.