There are so many that I won't even pretend these are necessarily the top 5 as of now, but I think they're all perfect. I went with a couple from the sixties and a few from modern times. Really though, I could go on and on with this topic. Come to think of it, I"ll be doing just that in my own brain as I pick the significant other up from work.
The Social Network- Mark Zuckerberg rejected and bitterly walking home to make history ("Hand Covers Bruise")
The Royal Tenenbaums- Margot's file ("Judy Is A Punk")
Before Sunset- "A Walts For A Night"
Killer of Sheep- Slow dancing in the bedroom ("This Bitter Earth")
Cria Cuervos- The three little girls dance in their room ("Porque Te Vas")