Hmm. It's probably a tie between RBY and BW's gym leader battle music. RBY is just like...well, when that song starts playing, you know it just got real. Then BW is kiiinda cheating, cause it gets two themes in one, but still, it goes back to RBY roots and is just awesome in its own right, however invokes a more friendly feel about it, as if you're just battling a good pal. And I kinda like that. But now that I've gone and said that about both, RBY will take the cake for me.