I knew this was coming. Here are my choices:
Name: Kid Icarus: Uprising - Main Theme/Main Menu
Universe: Kid Icarus
Game: Kid Icarus: Uprising (2012)
Link:
http://www.youtube.com/watch?v=k6nOPEMaWAw
Reason: A new theme for the new era of Kid Icarus. Since this will probably be the only Kid Icarus stage on the 3DS, I think it should be on the stage. So triumphant and fun to fight to!
Name: Kid Icarus: Uprising - Opening
Universe: Kid Icarus
Game: Kid Icarus: Uprising (2012)
Link:
http://www.youtube.com/watch?v=ts91h-WzVG4
Reason: I think it'd be fun to fight to, and upon closer listening, it actually contains a couple of important songs in the series (The old underworld theme and the Uprising boss music)
Name: Chapter 11 Medley (Viridi, Goddess of Nature & Reset Bomb Forest)
Universe: Kid Icarus
Game: Kid Icarus: Uprising (2012)
Viridi, Goddess of Nature Link:
http://www.youtube.com/watch?v=n3mm2ovLaUg
Reset Bomb Forest Link:
http://www.youtube.com/watch?v=LDAHOi9p01s
Reason: Since each stage in Kid Icarus: Uprising has an aerial portion and a ground portion, I think having a song to reflect that would be pretty good. Also, since it appears that the stage itself will change, I imagine the Goddess of Nature song will play until the reset bomb goes off (which I think is somewhere around the 1:30 mark), then the Reset Bomb Forest part will play until the stage goes back to normal.
Name: Magnus' Theme
Universe: Kid Icarus
Game: Kid Icarus: Uprising (2012)
Link:
http://www.youtube.com/watch?v=2kPwTTQb6D8
Reason: Magnus is a fan favorite character, as you can see by the views/likes/comments in this video. I don't expect him to be playable, but I do expect his theme song to show up. I also think it sounds like it would be awesome to fight to.
Name: Boss Fight 1
Universe: Kid Icarus
Game: Kid Icarus: Uprising (2012)
Link:
http://www.youtube.com/watch?v=u2S2h24xuZI
Reason: This song seems like a no-brainer to me.
Name: Dark Pit
Universe: Kid Icarus
Game: Kid Icarus: Uprising (2012)
Link:
http://www.youtube.com/watch?v=QG77HTdreh0
Reason: This song takes a while to get going, but I feel it provides a nice contrast to the epic orchestra and hard rocking of the previous tracks.
Name: Underworld Tower
Universe: Kid Icarus
Game: Kid Icarus: Of Myths & Monsters (1991)
Link:
http://www.youtube.com/watch?v=relroNy1NSE
Reason: This would sound awesome with modern instruments, and I think it would be nice to pay tribute to the first appearance of the series on a portable system.
Name: Battle With Saturos
Universe: Golden Sun
Game: Golden Sun (2001)
Link:
http://www.youtube.com/watch?v=iEjqqUTz-us
Reason: This is my dangerous pick, since it being here hinges on whether or not Isaac and a Golden Sun stage don't make it in (since I think that this song would be on a Golden Sun stage). Anyway, I think this would be a good place for this song to appear on, plus it's a fan favorite. Motoi Sakuraba composed the music for both Golden Sun and Kid Icarus: Uprising, both games are handheld titles, and in a meta/far-out reasoning, since a Golden Sun song appeared on a Metroid stage in Brawl, I think it would be cool for a Golden Sun song to appear on Kid Icarus in Sm4sh (since Metroid and Kid Icarus were "sister" games.)
Well, that's my list. I don't expect the Kid Icarus Overworld/Main Theme to make an appearance on this stage, since I think the 3DS stages will focus more on current/portable titles, so that's why I didn't include it (Although it does show up in the Uprising Opening track.) Also, I originally had The Tunnel/SR388 Surface from Metroid II on this list, but I figured that would be on a Metroid 3DS stage so I took it off.