Metroid Fusion.

[afolloweroflight]

In particular one of the boss themes (the one that plays during the fight with Serris and certain other bosses). I have the rip if anyone needs it.

[X]

So far as I know, each boss from Fusion pretty much has its own boss music. That goes for Arachnus, Serris, Zazabi (Pogo), B.O.X., Neo Ridley, Nightmare, etc. even though a fair few of them do sound a bit similar (like Serris and B.O.X.).

Actually... vs Serris and vs B.O.X. would make for a couple good candidates. I'm honestly surprised that nothing from Fusion has been remixed yet. It has a pretty cool soundtrack... :? I've always been especially fond the Sector 5 (ARC) BGM myself. 8)

[afolloweroflight]

Actually Serris and Archanus have the same music, but that's the one in particular I'd like remixed.

If not that, than the Section 4 water music. Why I'm not particularly itching for a remix of the sector 1 music, while excellent, is because brawl already has it's own great remix of that.