It's really hard to pick. Nitpicks about the gameplay aside, the "quality" argument is muddled by the fact that one game can use CD-quality audio/samples and the other can't in addition to being able to just have way more of it in general. As others have said, it's also hard to objectively parse Trigger for me as so much of that game is wrapped in the nostalgia of my childhood, wherein I literally developed most of my early musical ear and transcription skills by making midi's of the OST, and I never owned a playstation and didn't play Cross until my mid-late teens. That being said, Cross has some obvious marks of compositional improvement from Mitsuda, more widespread/consistent use of leitmotif and broader thematic development and instrumentation use (though Trigger was no slouch in that regard either). IMHO though, while Trigger has a better OST on average, the high's of Cross' are unbeatable. Time's Scar is just hair-raising.