This is a pretty cool mix of the Gym Leader theme from Pokemon Stadium. I remember turning on the N64 early in the morning with my Pokemon Blue and heading into the Prime Cup to take on what I thought were the toughest trainers available. Oh those days...
The best theme in the game in my opinion. It's got a triumphant victory kind of feel to it.
I wasn't as big of a fan of Stadium 2's music, but I've got fond memories of trying to make my Round 2 Master Ball Challenge Cup team work with this music in the background.
I really do think Stadiums 1 and 2 filled the role that competitive Pokemon does for me today.