When I first read GoF, I thought that Harry would end up with Hermione. I think she evens out his 'defects'. I wouldn't say he's stupid, he's just very stubborn and temperamental.
I don't see how she could be with Ron. Ron is of moderate intelligence, he has not many challenging personality traits. I just don't see Hermione barefoot and pregnant, as i think that would happen if she's with him.
Just my opinion, I might be wrong.