Well, there's a lot of good ones in the bunch, but I think I will go with Welcome To The Moon Tour. It's a bit generic, yes, but generic ZUN is excellent ZUN. It has a kind of forward marching energy that more of his songs should have. Honorable mention to Far Side of the Moon.
What is your favorite Touhou fangame?
Among the many media Touhou has covered, it has also spawned many high quality fangames. CHOOSE.
I haven't played very many, but I have fond memories of Labyrinth of Touhou. Not the kind that would make me ever touch it again with a ten foot pole, but it left quite an impression on me after I finished it. Plus, the music. Borrowed music, yes, but... *_*