Oh, jeez. It's rather difficult to just pick one, but lately, my current obsession is "The Bachelor and the Bride" by the Decemberists. It's full of passion, and gives me chills every time. It tells such a great story, as do all the songs by the group.
I would go with "Where is my Mind?" by the Pixies. That song comes in the End of my favorite movie of all times "Fight Club" and it is just Breath-taking when the song plays and all the buildings blow up.