Harry: Because they have an awful lot in common and don't bicker. Hermione is the only one who will calm him down and the one who Cho is jealous of in the fifth book because of her closeness to Harry. They protected each other in POA and OoTP, and though Harry would do it for anyone, J.K. specifically wrote it was Hermione. Hermione was who was worried about him in GOF. In the first book, Harry probably was the one who worried about her in the girls' bathroom more than Ron. They're completely meant to be together, and Hermione doesn't love Ron! But I still think she would like Ron, but not forever.