I am kind of behind the times on arcade emulators on the Xbox. Are there any games that the PC version of Final Burn Alpha supports that aren't playable at all on the Xbox?

I think G-Loc and Turbo Outrun are two (I could be wrong). Are there others?

Not sure, but getting those 2 games alone playing on Xbox would be awesome!
Especially Turbo Outrun...

well off the top of my head.
the fd encrypted games like as you say turbo outrun,dd crew,desert breaker,ab cop,...
i would love to see the arcade version of cotton emulated on the xbox,it is playable on pc fba but not xbox,unfortunately its another fd encrypted game.
the pgm games dodonpachi 2 beestorm and knights of valour 2 would be something but i think that might be pushing it.again these 2 games are playable on pc fba.

DoDonPachi 2 isn't playable in any emulator. Kov2 with its arm7 protection processor is quite slow, too slow to emulate nicely on xbox, and too complex to simulate the arm7 (unlike kovsh).

yeah i thought kov2 would be to much for the xbox and i dare say martial masters would be the same.
yeah your right about ddp2 i remember trying ddp2 on a newer biuld of mame.

I just added G-LOC, Turbo Outrun, and Cotton. Do any of the PGM games work on the Xbox?

knights of valour
knights of valour plus
oriental legend
these games play well on the xbox under fbaxxx and coinops reignite.

pretty much any games that don't use the arm7 run pretty decently. You can get a pretty decent speedup with kov2 [and most other arm7 games] by detecting idle loops in the arm7 and skipping them [which I've done for the most part], however, martial masters uses the arm7 quite a bit for extra processing power, making it much too slow.

i think desert breaker would be a good choice,looks like a really good mercs style game.

I realise not everyone feels the same, but I would love to see stuff like martial masters and knights of valour 2 added, even if they run too slow (especially if theres an option to disable sound or frameskip etc). Id love to test that stuff on my trusty-modded xbox aswell, if they had some good stuff that worked on them then more people might get them and we could one day see the most squeezed out of them? idk just a thought.

Anything you add will be appreciated