This article is one of the best articles I've read regarding the subject:
10 Reasons I Kissed Halloween Goodbye
You may disagree with the article's reasons (though be sure you are disagreeing with the article rather than Scripture :-) ). I hesitate to even post anything about it as I'd kind of rather ignore it in some ways as it is so controversial and touchy for most people, but I decided to post it anyway because the article's reasons are so closely aligned to our family's reasons. I don't really want to get into a huge debate over it, but this is our view in case you are interested. And if you disagree....I'll still love you, anyway :-).