Yes, I know they weren't really a couple. And I guess I could have put them as one of my favorite onscreen couples (they were scorching there too!), but I loved their real life relationship. They were best friends and loved each other dearly and took care of one another.
Montgomery Clift and Elizabeth Taylor in A Place in the Sun. These two are a textbook example of good chemistry. And they are so beautiful together you might just hurt yourself looking at them.