My thoughts:
I believe that Aerith never loved Cloud but he just reminded her of Zack, the man she DID love.
Zack of course loved Aerith, but then he died protecting Cloud.
Tifa loves Cloud, but never tells him for the sake of their friendship (although I thought they might have come closer during the movie time line).
Cloud felt attraction towards Aerith (I'll concede that, although it might be because he mimicks Zack's feelings for Aerith) however, he has a feeling of reverence towards her after she dies, a type of love for your guardian (he called her "mother" in the movie).
I think Cloud had a crush on Tifa when they were kids, but that went away eventually (LOL, he got into Shin-Ra and saw so many hot dudes he forgot about women

).
But seriously, Aerith and Zack seem like the obvious pairing, especially since their both dead now. If Zack was still alive, those two would be together before Aerith died, or something.
I would like to hope that Tifa and Cloud would get together. They have potential, but it's all on Cloud to pursue Tifa since she's doesn't want to ruin their friendship.
As for Vincent, Lucrecia, and Hojo...
Vincent did love Lucrecia, that's obvious.
However, I doubt there was any romantic feelings between Hojo and Lucrecia.
I think Lucrecia wanted to get away from Vincent because she felt too guilty about the death of his father and ran to Hojo instead.
Hojo comes of as a little narcissistic, but it's more about the pursuit of knowledge, no matter the cost. If he loves anything, it's probably himself.
Lucrecia is hinted to love Vincent as well, but you, all that stuff happened, so it didn't work out.
I guess those are the only real three ways suggested in the game.