I am really into off beat love story like, a couple being together and finding out the sibling. The story where a sister ask her brother to give her a child to make her husband happy.
some random ideas
two lonely workaholic get trap in the offices to gether. at first they hate each other then fall in love.
any incest story that has more to it than just relatives having sex.
a guy picks up a hooker but pay her to spend time with him. she slowly fall for him and changes her life.
two childhood lover find out after 20 that they have the same father a week before the wedding.