Hm, so many great songs to pick from! Oh well, let's see:

Kuwashima Houko - Shinkai no Kodoku

- It's most likely because of the moment.. but this song makes a tear well up in the corner of my eye each and every time I hear it. Poor Stellar.

Tamaki Nami - Heroine

- At first I thought it was "heroin." Unfortunately, that was not the case. And yeah, that is the only reason I listed it. That, and it's by Nami.

Tamaki Nami - Reason

- I'm in love with this song. Literally.

Gundam Wing - Rhythm Emotion

- Pure sexiness. I fucking love the beat.

Tamaki Nami - Realize

- I don't think I need to add any more praise than already has been given. Oh, who I am shitting? This song makes most other GUNDAM songs seem like shit. Yes, it's that good.

Tamaki Nami - Believe

- The beginning, yeah. And it's by Nami. Can you tell I love Nami? I bet you can.

TM Revolution - Meteor

- Lovely song which is more on the soft side. Didn't this song play before Heine's death in GSD too?

I'd list more, but I'm lazy so that will have to do for now.