Wedding Songs

I am having so much fun planning our wedding! Seriously! There is so much to do, but it is coming along so well and it's fun fun fun! I have done so much of the big stuff, now I'm working on the little things. My project right now is picking out music to be played during the ceremony and reception. I think the reception is pretty well set, we just have to set a few songs. But the ceremony is harder, because I want most of the music to be instrumental. There are so many types of songs; preludes, the processional, the Bride's song, the Unity candle song, the recessional... I found this awesome site that has been super helpful! There are some absolutely beautiful songs on this site, and now I'm having a hard time deciding.

What songs did you play at your wedding? If you're not married, what songs do you want played at your wedding? Are there any "must-haves"?