I was fortunate enough to get the Arrow Video Limited Edition version of An American Werewolf in London, a couple of days ago and really liked what was included in this version. Not only did it come with a hard slip cover, but also a booklet about the production, a reversible cover sleeve, and a double sided poster (as seen below).
I believe that this movie has the best transformation scene practical effects that has yet to beaten by any other werewolf film. To be fair, I have not seen every werewolf movie, so I could be wrong.
This is a limited edition version and I am not sure how many will be left, so I would CLICK HERE, or any of the pics below, if you are interested.