It took me a few hours to make this, but, here it is!  It's a video about 7 and 9 with the song "Still Alive" from the game Portal, but this is a specific duet version with GLaDOS and Jonathan Coulton (the guy who wrote the song) singing it.  I fell in love with this version the first time I heard it, and after finding a WALL-E/EVE video with this version, I figured that it fit for 7 and 9 as well!

Spencer7271985 mixed this version, and DustinWilson1992 converted it to an mp3, so I have to give them credit.

JoCo owns the original versions of the song.  9 belongs to Shane Acker.