The Stage 1 themes from PCB, IN, and UFO. They're not specifically my favorites, but they're energetic and I think stage 1 themes are good for quickly feeling motivated (which I assume isn't a coincidence, seeing as they're made as the first songs you hear when starting a run)
The Capital City of Flowers in the Sky and
Mystic Oriental Dream ~ Ancient Temple because I love the airiness and the pace to them (I like the airy feel of the PCB soundtrack in general)
Fall of Fall ~ Autumnal Waterfall, not sure why
The Bridge People No Longer Cross. Again not sure why, maybe because it feels mystical/magical
Lullaby of a Deserted Hell because it's calming and cheerful
The Sealed Cloud Route, kinda for the same reasons as
The Bridge People No Longer CrossSky Ruin, because I love this song and it sounds like a traveling one to me
The Traditional Old Man and the Stylish Girl. Usually I wouldn't pick a boss theme for a walk but this one has a cool folk feel to it and IMO it retains the airy feel of its stage theme
Sky RuinWelcome to Youkai Temple. I kinda associate this with purposeful walking, maybe 'cause its stage background involves a wide path
Let's Live in a Lovely Cemetery, for the same reasons as
Lullaby of a Deserted HellMagical Storm. I love this song and its airy, cloudy feel
Most those songs weren't any of my particular favorites, but I guess the fact I don't listen to them as often makes them more mystical, which is part of why I think would keep me going on a walk