Definitely songs...they stay with me longer than movies, and I can replay them in their entirety in my head (or out loud) whenever I want. Most of the people who have gone through my life have been music lovers, and each has songs that belong exclusively to them in my memory.
Lol...that's what they should be calling it. When I was pregnant my ex would get upset at me in the afternoons because I was just using nausea as an excuse then, so he said. When I said that it's pretty much all the time, he said, "No, if it was all the time then they wouldn't call it morning sickness."
Hmm tough one. Songs do set the soundtrack to your life and all that but films have a special place for me also. In fact films sometimes make me nostalgic for times I've never seen and places I've never been.
Songs without a doubt. Reason being is that they traveled better. With today's technology this might not be the case so much anymore, but when I was growing up, I always had music playing on the house stereo, on the car radio and where ever my boom box would travel. If I didn't have mine, somebody always had one. I am sure depending on the age groups you ask, the more common answer could change with younger generations since there are portable t.v.'s and DVD players everywhere now, you can even watch on some phones now!