Aaron : This is not me, Half, Taipei Dreamin' (Fall In Love With Me OST), Unstopabble Sun(Just You OST), Your happiness is my happiness(I Am Sorry I Love You OST) these song are unforgottable for me.
Bii: Happiness has nothing to do with it, I will be at your side (Love Around OST), I'm Still Missing You, We Are Walking in Love(Someone Like You OST), , Back In Time, Tender Love(Bromance OST), I will miss you (Prince of Wolf OST), All You Did (Better Man Ost)
Jay Chou: Shouldn't Be (Ice Fantasy OST)
for me, Aron and Bii are my favorite when it's came to an ost <3
surprisingly, I watched most dramas that has Bii ost on it. even tho I'm not even sure he would sing an ost for that. I hope Aaron would sing more OST in future.