Secret by Maroon 5 makes me think of Rhage and Mary from JR Ward's Lover Eternal. I don't know why, maybe because it's just so earnest:
Lux Aeterna (Requiem for a Dream) by Clint Mansell makes me think of Charlotte Featherstone's Anais and Lindsay from Addicted; one of my favorite reads last year (you've got to get to about :30 before you can hear the music):
Yet another JR Ward couple (hmmm...I must be getting excited about my boyfriend John Matthew's book - Lover Mine!!!), this one is Zsadist and Bella - Going the Distance by Cake:
In this case I know exactly why - it's the line where they say "She's all alone in her time of need," which brings to mind the hottest, tenderest images of Z and Bella....*sigh* Really the whole song reminds me of what's going on in Z's head after she leaves. It works!