Spinach Rag vs. Treno:
Spinach is a very cute piece for piano while treno is also a good one too. though I admit it's simpler, it's such a friendly piece when you learn to play it. so Treno and it's simplicity gets my vote. ^^
Fisherman's Horizon vs. Dali:
well I first heard Dali and I already fell in love with it. it's so sweet and there's really something so nostalgic about it. while FH.. hmm it's nice too and I've heard it's pretty popular but personally it makes me too sad in a way that's painful. haha I dunno but maybe it's bcoz I get reminded of what the Winhill town has turned into during the present. Needless to say I liked the old BGM during the dream as Laguna better.
FFVI Music vs. FFIX Music:
an SNES music vs. PS? okay I know this might not be a very good comparison but to tell you what, FF6 music is SO brilliant and WELL-loved by many. it definitely stands out among SNES games at its time and I've heard people claim that this is still the best OST made in the series. now I personally prefer FF9 music more. for me if FF6 is a great classic, this one is no exception too and it further expands what 6 can give. should I vote according to their quality for their time, 6 would've win but I LOVED 9 most and along it's music. nuff said.
Rikki vs. Mayuko Aoki:
I think they sound very similar but to make it short Mayuko Aoki has a cooler voice IMO. All her songs in the X and X-2 vocal collections are well-sung and I like them.
Faye Wong vs. Angela Aki:
Faye Wong for me definitely. I already gave Angela's version a chance but Faye's is just perfect and classic. The first time I heard this song she reminded me of Rinoa and I thought that's how she's supposed to sound like(which is false isn't it).
that's about it.