Yeah it is graceword, I don't think there would be many who would disagree... I've been looking and that seems to be the only one. Most secular films tend to give a bad view on marriage..mostly.
I'm actually going to disagree on this, it seems in more recent movies they've actually been getting a better idea. Unfortunately most of these are loaded with perverted humor and sex. But just to give a couple examples of what I've seen, Date Night with Steve Carrel and Tina Fey is about a couple who have kind of hit a boring rut in their marriage and are looking to do new things to help revitalize their relationship, Couples Retreat is about a couple wanting to go on a retreat to a vacation spot that doubles as a marriage counseling seminar and they rope their married friends to come with them, and the movie Extract is, yet again, a couple at a dead spot in their marriage, the wife has an affair and the husband tries to but horribly fails. The end of the movie leaves the viewer with the idea that they've both regretted their actions and are willing to stay together and work things out.
I have a hard time recommending these movies to watch because of the statements I made above about content. However if that thing doesn't bug you too much, you could check them out. Date Night and Couples Retreat are PG-13, Extract is R