Building A Mystery ] Sarah McLachlan
I think the lyrics speak for themselves in this song. I think most of the song revolves around what's going on during Advent Children. "Dark side's light" has some meaning within in and "vampires roam" reminds me of Vincent. In AC, Cloud obviously lives in a church. "Search for the ghosts in the halls" pretty much describes Aeris' "ghost". And then, let's face it. Cloud is a mystery.

Even In Death ] Evanescence
I remember hearing this song for the first time I immediately thought of Cloud and Aeris. I noticed this was on the Hikari site, too, so I know it's no lie. This song strongly relates to Cloud's feelings about Aeris' death. He believes that she can't possibly be gone, even if the rest of the world says so. The love between him and Aeris still continues to grow even if she is dead. It goes on forever.

Helena ] My Chemical Romance
Helena happens to be my all time favorite song and I thought it could really relate to Aeris and Cloud. Helena is about losing someone and not wanting to say goodbye. As you may already see, this is about Cloud not wanting to say goodbye to Aeris and how it'd be better to pretend to leave and that they should stay together.

Here On In ] South
I love South and all their music, but I feel this is the song that most connects with Cloud. I guess I don't need to point out why this song goes, but I must point out an obvious line that automatically told me that this song fit. "I've lost more inside than the spirit that's died". Kind of obvious what the meaning of this is.

Iris ] Goo Goo Dolls
If you have not yet realized it, this is the namesake of this shrine. Personally, I think this is the song that most describes Cloud's feelings. He doesn't want the world to see him, because he feels that they won't be able to understand the things that he's gone through. As for Aeris, he's feels somehow safer around her and feels that he can talk to her about his feelings. This song basically tells how Cloud has suffered so much and is still afraid to show how he feels.

Passive ] A Perfect Circle
I think this song relates more to Sephiroth and Cloud. It's more likely to be from Sephiroth to Cloud. How Cloud could have been like Sephiroth, but chose not to. And of course, how they're perfect enemies.

The Red ] Chevelle
This song seems to be between Sephiroth, Cloud, and Aeris. Most likely, it'd be about the time of Aeris' death.

Wonderwall ] Oasis
Wonderwall is a really good song to describe them. It's basically another song from Cloud's point of view. "Now you should've somehow realized what you gotta do" is basically about how Aeris realizes that she must summon Holy to stop Meteor. There is also a line that says, "You're gonna be the one that saves me" which is about how Aeris helped Cloud into opening up and saved him from himself.