It depends, to me, a lot on how it's done. One thing I really appreciated about Peggy and Steve's romance (even though it was technically unnecessary to the plot of the story) was how the film made it a point to show the parallels between them. Peggy was interesting on her own as a woman fighting for a place in the military in the 1940s. And this meshed really well with Steve, who was always held back because of his size and health. They shared something that made them interesting even WITHOUT them being into one another. I really appreciated seeing Peggy in The Winter Soldier again as a result even though it was (understandably) a short scene.

Where I've consistently been disappointed with Pepper from Iron Man, though, is that SO MUCH of her character revolves around conflict with Tony. I was really excited to watch Iron Man 3 given that she was the CEO, but it seemed as though everything about her problems revolved around Tony. And…I just have a hard time finding that compelling personally.