Cool songs. I'd forgotten how ominous that Paper Mario song is. It's been a long time since Bowser was scary! As for Grandia 2, I'd be willing to bet that the guitars and drums are real but the other instruments are synthesized. The brass certainly is, though it is pretty good. Definitely an awesome song though.
As for a favorite of my own, I'm gonna share a normal boss theme because I missed last week's post you did lol. This is "The Edge of Green" from Radiant Historia, a superb RPG on DS. Composed by Yoko Shimomura.


 At least they're easy to switch out, I guess.