I've sampled a large amount of video game music, and I find there are so many grand gems of sound out there. (I contend that there ought be radio station dedicated to music from video games).
I mean, I could point to some particularly striking or moving arrangement, but, if I'm being honest, I have to choose a song based on the mundane reason that I constantly have it stuck in my head:
Lilycove City's (Ruby, Sapphire, and Emerald) music captures a juxtaposition between the hustle and bustle of an port city with economic importance and the reflective lifestyle that the sea, being such a powerful force and a cradle of life, provokes. It's calming and energizing at the same time. The careful, gentle rythm
clashes with a moderate intensity to create this feeling.
Plus, not to mention, it's mundane and charming enough to play in my head without becoming grating. It's like the elevator music of my life.