mscbryk, I've listened to several of them and enjoyed them, even though I feel strongly that they've taken the Dark Shadows story in a direction that I don't accept. The stories I've listened to can be taken on their own terms, although they fit into the overriding story that has been created.
My favorite by far is Clothes of Sand, with Kathryn Leigh Scott. I thought it was my favorite simply because it was a good story that took place principally before the end of the series. Now that I think about it, however, it's also because, since it used heavily some already established plotlines of the main series, there was more time within the format to tell the story. I don't really believe the story, but it was a good one anyway, and it made some connections that I hadn't thought about before.