Walked down the aisle to: Real Love (Regina Spektor cover of John Lennon)
Signed papers to: The Lengths by The Black Keys, something by Jose Gonzalez, a couple of others
Walked out to: Learnalilgivnandlovin by Gotye (The BEST choice!)
First dance to: Regina Spektor

SIL had
Songbird by Eva Cassidy
2 x Enya Songs
Beautiful Day by U2.

Now, I am obsessed with the song "Sweet Disposition" by The Temper Trap. Not 100% sure if it's a good choice, but I just love it.