First of all, DH and I watch Supernatural too, who knew so many scrappers were fans!
I either have on a movie/ show that I've seen a million times (so I'm less distracted) or some music. Such as: Notting Hill, New In Town, Anchorman, Saved by the Bell, Glee, etc, etc.
I like all different kinds of music, so it varies, but often I like to listen to music relevant to what I'm scrapbooking. If I'm scrapbooking a concert I went to, I'll play that artist. If I'm scrapping a certain time of my life, I'll play music that makes me think of that time.
Often though my background noise is that of my DH's video games. :-) He has a man-cave, but sometimes we like to just be in the same room so he'll come out to the living room by me and play. Some of his games actually have somewhat soothing sounds, like Assassin's Creed, Fable, Minecraft.