ok i like Shota and bishounen. (not at the same time mind you)
my favorite shota couplings just have to be the cute and innocent type. (you know how when boys kiss for the first time cause they don't know how to do it with girls and they don't wanna look stupid?). It happens among younger and younger kids these days.
My fave Bishounen couplings are always Bishounen that are pretty but exude strength, paired off with a slightly more masculine bishounen (you know shorter hair sometimes spiked but still a pretty face).