The handful of songs/albums that make me feel very deeply are among my most treasured possessions. I've heard them so many times that they are completely ingrained in my head, but I think about them and put them on very rarely because I like having something that makes me feel a certain way, if that makes any sense. There are a few movies that are the same way for me.
The worst are the few songs that played over the PA at various jobs I worked - some of them are very bad songs attached to good memories.