Which one do you prefer? Which do you think is better?
Neither one is better than the other, nor is one preferable to the other.
Er...ZFC, because it matches my curtains.
This doesn't really strike me as a "preference issue". You can prove the same things in both, so, as a fan of mathematics, I really see no reason to pick a side, since it's unlikely that I'll ever encounter a level of argument "low" enough that the difference is relevant.
Separate names with a comma.