I'm going to toss in some Secret of Mana.

First, the boss theme. Danger!


I love the changes and movements in this theme. It truly is an epic throw down piece. You start with the warning and frantic attempts to evade the boss. You then cycle into the phase where you're learning techniques and strategies. Then finally, it shifts into the final motif, where you are laying waste to the boss in an awesome finale. It is a great theme that fits the stages of the boss fights so well.


Second, one of the most epic boss themes ever: The Oracle.


What makes this theme? The fact that it is so epic that it can get an endgame boss to just sit still and headbang to it, pretty much indefinitely.