Paul tells us to even avoid the appearance of evil, good advise, one would be wise to follow it. However, there is a bit of a problem in our post-Christian North American culture. Christians have vilified nearly everything at one point or another. What makes this really confusing is that many of these things that have been called 'evil' turned out to simply be things. Rock and Roll, alcohol, playing cards, role playing games, and the list goes on. Sure some people have done some really screwed up things with these - but hell we've done some really screwed things with the bible.
So how is a Christian to avoid evil when it is so hard to figure out what is evil and what is just mundane? I think it is easy to have a list of taboo things - but really this is just part of the malaise of Christiandom. Wouldn't it be much more honouring to people to help them to walk through the morass of societal values on their own? Wouldn't it go a long way in helping each other to work out our own salvation in fear and trembling and spur us on towards love and good works? I think it just might.
I don't think there is an easy answer to a lot of things Christians write off as 'evil'. I know that my experience hasn't mapped too well to the Christian expectation. Harry Potter, for example, has not encouraged me to take up Satanism or witchcraft. Quite the contrary, Harry has encouraged decent Christian morality and encouraged me to make the right choices, not the easy ones. Maybe I am just able to find good in evil things - but just maybe the things aren't as evil as we had been led to believe.