Eh, I suppose I simply have different taste. It happens.
In no particular order, my favorites from Diva F since I tend to enjoy playing certain songs more than I enjoy listening to them, and vice versa.
Senbonzakura (On a semi-related note, if that Senbonzakura Miku figure comes out at a decent time, it might well be my first and only Miku figure).
I can't really decide a 5th, so I'll just go with World's End Dancehall, but it's pretty much equal with a few others.
I enjoy playing the songs that, on Hard mode, have lots of triple sets. Remote Controller, DYE, and Monochrome Blue Sky are some of my favorites to play, other than the above list, because of that. On the opposite end, I am absolutely incapable of properly playing What do you mean?! and, to a slightly lesser extent, the MMO song, because of the flying equations in the background. They distract me too much.