Actually, Cloud is a schizophrenic male chauvinist who hits the girls... I'm not sure if a man like that can feel love ;D ... (And I'm not feminist!)

But, trying to answer the question, I don't think he loves one of them... With Aerith the relationship was to short... I really don't believe in love at first sight or in loving someone when you are starting to know her/him, that's just liking her/him... I think love require years ...
He only feels regret for not saving her... which is normal in a case like this even if you don't feel love...

But I don't think he loves Tifa instead, cause I think that the same regret of losing Aerith without saving her or asking her pardon for hitting her, don't let him feel love... And well, she is just a friend of him, and a friend who will be more happy having a life with Barret than with him... Barret won't hit her... :B


//Sorry, I never liked Cloud xd