I didn't think any of those were particularly good in the romance department (except Horimiya which I don't know much about). World God had the most actual romance... even if it wasn't with the same couple.
Horimiya is soooooooooo wholesome, it's a very simple story, actually it's not even a story it's just slives of the life of a bunch of high school students, but it's just too wholesome!