As far as Pokemon goes, I’ve always been partial to the Team Galactic battle theme from DPPT. And though “catchy” doesn’t quite do it justice, the night theme for Jubilife City, also in DPPT, is tremendous. Walking into that city for the first time at night was one of the defining moments of my video game life.
And the Shiver City theme from Paper Mario is unforgettable.
I don’t think anything will ever beat Still Alive from Portal though.
I’ve had a copy of it for about ten years now and still haven’t watched it.
I plan on it, but I know enough about it that I know I have to be in just the right mood.