Glosoli- Sigur Ros (i'm worried this one won't go over well but i think i'll give it a try)
Depends on how she is with music. If she's the kind of person who really gets into the mood a song sets, it will absolutely be perfect.
It also depends on her tastes, too. If she doesn't like heavily-distorted guitars (or does like the ending but doesn't want the long wait for it), don't go for this song. Instead go for "Hoppipolla." Short, sweet, perfectly timed. I ended up switching "Glosoli" out on my mix for it. Go back and listen and see how it fits if you really want to be sure of it.
Anyway, keep tweaking it as you see fit, and *always* check lyrics. Pretty melodies that end up being about cheating are aaaalways a terrible idea. And don't be afraid to add a few faster songs. Life ain't always a slow dance. ^__^