Aerith and Zack have romantic feelings for each other but he died.
Then Aerith and Cloud Strife became an Item but she got killed by Sephiroth. If you think about it Aerith might have ended with Zack in the after life since her death kind of reunites them.
Which Final Fantasy 7 couple do prefer?
Aerith X Cloud
Aerith X Zack.
Zack is her first love and I think the only reason she fell for Cloud is that he reminds her of her. I attached a poll on this thread so you can vote for your prefered couple.