as great as it is, the VI OST doesn't grab me as much because i've never been a hardcore fan of the game itself (maybe because i played it years later? but that wouldn't explain IV being a favourite).

for me VII's score, while perhaps less sophisticated from a technical level (arguably poorer instruments/samples used, though they were well-suited to the game's mood) and maybe even from a compositional level, is more impactful because i really loved the game at one time. also it takes the earlier version of what would later become Aeris' theme (that short section in Aria Di Mezzo Carattere) and expands on it to make it even more emotionally resonant. aeris as a character would have very little emotional impact without Uematsu's score imo