High Society - the guy isn't ugly, but he's poor and he's neither popular nor unpopular.
A Gentleman Dignity - features 4 couples, one of which is poor guy / rich woman. This love line also happens to be a noona romance, if you're into that.
Ugly Alert - at the end of it, I didn't fancy this drama that much, but you might so ...
Hyunhætan Marriage War - if I'm not mistaken
Ojakgyo Brothers - features the love lives of 4 brothers, two of whom were involved with women richer than they were.