These are the ones I've got on my draft list so far...

At Last - Etta James
I Will Be Here - Steven Curtis Chapman
I'm Yours - Jason Mraz
Forever - Ben Harper
Better Together - Jack Johnson
Saving Grace - Pete Murray
Lovesong - The Cure
Feels Like Home - Chantal Kreviazwk (this one's from the movie The Notebook, so romantic! )
Grow Old With You - Adam Sandler