I want to nominate "And I Love You So" by D McLean
I'm sure others will find these lines a bit too simple and corny, but I'm comfortable with:
The book of life is brief, and once a page is read, All but love is dead, that is my belief.
Also:
And you love me to, Your thoughts are just for me, You set my spirit free, I'm happy that you do.
When I think about love in terms of my own mortality, and what I hope to be lucky enough to take with me; these words just seem to work!