I love the trope where one has to bandage or look after the other one if they get hurt or sick, or both haha.
I'm also a fan of the two characters disagreeing only to find an understanding and come together and fall in love. I like seeing two characters actually disagree over fundamental differences as it reveals who they are as characters and I like the feeling of sitting there going, "ooooo, this is hard cause they both have a point," 
Also, big fan of female characters who feel well rounded and flawed beyond being clumsy. I like em to have a little fight in them.