I also have a good number of posters for films I havent seen. Some flicks can be really awful, but have cool or captivating artwork. And some were gotten simply because of the art that caught my eye. Others are for movies I just have gotten around to seeing yet, but plan to.
Movie posters will always be tied with their respective films; for me, whether I have seen the actual flicker or not is secondary, especially if it isnt worth the time to watch (but the poster is a thumbs up).