Much which has already been posted on, I too was prohibited from owning or participating in. So, I thought I would add to the list -
Watching movies Rated PG-13
My father invented this and tried promoting it in the congregation, but it fell flat. His belief was that they were R-Rated Lite movies and therefor should be avoided. He adopted this policy at the worst of times. I was in middle school and two important movies were released - Indiana Jones and the Last Crusade and Batman. Batman was the one that really broke my spirits. I was and still am a huge fan of comic book heroes. I had all sorts of Batman t-shirts and memorabilia. I remember friends in the congregation called me "The Batman".
When Batman was released everyone was sure I'd be the first in line. When I said I was not allowed to see it I was asked why. When I stated because it is Rated PG-13 everyone gave me an odd look.