Sleepless Night of the Eastern Country is god-tier, but it's also the only good song from StB. Wind Tour is nice, I guess.
For PC-98, PoD.D by far. Reincarnation, Oriental Love Consultation, Tabula Rasa, Lost Dream (overrated song, but still quite nice), and Fight It Out! are all wonderful. Honorable mention to LLS, just for Alice Maestra.
For Windows, MoF definitely. I like...well, just about everything that's not Candid Friend! Special mentions to Dark Side of Fate, Gensokyo the Gods Loved, Fall of Fall, and Faith is for Transient People (by far the best song in the series).
Candid Friend is fucking awful though.