Some of my favorite Neo music is, and in no particular order:
. Magical Drop II (Justice has one of the coolest soundtracks of all time in my book)
. Viewpoint I can't think of one bad track on that game)
. King of the Monsters 1 & 2 (Astro Guy's music in the first one is still the shit to me)
. The Samurai series (to me, part 4 was the weakest of the batch, but there are a few tracks on there, especially Genjuro's, that save it)
. The KOF series (Kyo's Esaka soundtrack is still tops here)
. The Real Bouts (particularly Terry's, Yamazaki's, Geese's, Duck King's, and Billy's)
. The first Art of Fighting (though the jazzy sound in part 3 is very interesting and cool too)
That's all I can think of for now, though I know there's more I could think of later.
*And on a side note, and not to stray from the subject, but speaking of music, Drunken Shaolin Devil, have you picked up the Samhain box set yet? Great stuff, especially getting to hear the original version of Twist of Cain...*